Jake Ezell Sandbox 2 - Revision history

Jake Ezell: /* Malate Dehydrogenase */

Jake Ezell — Mon, 29 Mar 2010 19:30:40 GMT

Malate Dehydrogenase

←Older revision		Revision as of 19:30, 29 March 2010
Line 2:		Line 2:
	Malate Dehydrogenase (MDH)(PDB entry [http://www.pdb.org/pdb/explore/explore.do?structureId=2X0I 2x0i]) is most known for its role in the metabolic pathway in the tricarboxylic acid cycle or Kreb's Cycle which is critical to cellular respiration in cells [http://en.wikipedia.org/wiki/Citric_acid_cycle]; however, the enzyme is also in many other metabolic pathways such as glyoxylate bypass, amino acid synthesis, glucogenesis, and oxidation/reduction balance <ref>PMID:12537350</ref>. It is classified as a oxidoreductase[http://en.wikipedia.org/wiki/Oxidoreductase]. Malate Dehydrogenase has been extensively studied due to its many isozymes <ref>PMID:20173310</ref>. The enzyme exists in two places inside a cell, in the mitochondria and cytoplasm. In the mitochondria, the enzyme catalyzes the reaction of malate to oxaloacetate; but in the cytoplasm, the enzyme catalyzes oxaloacetate to malate to allow transport <ref>PMID:20173310</ref>. This conversion is an essential catalytic step in each different metabolic mechanism. The enzyme malate dehydrogenase is composed of either a dimer or tetramer depending on the location and organism <ref>PMID: 9834842</ref>. During catalysis, the enzyme subunits are non-cooperative between active sites. The mitochondrial MDH is complexly, allosterically controlled by citrate, but no other known metabolic regulation mechanisms have been discovered. Further, the exact mechanism of regulation has yet to be discovered <ref>PMID:7574693</ref>. Kinetically, the pH of optimization is 7.6 for oxaloacetate conversion and 9.6 for malate conversion. The reported K(m) value for malate conversion is 215 uM and the V(max) value is 87.8 uM/min <ref>PMID:19277715</ref>.{{STRUCTURE_2x0i \| PDB=2x0i \| SCENE= }}		Malate Dehydrogenase (MDH)(PDB entry [http://www.pdb.org/pdb/explore/explore.do?structureId=2X0I 2x0i]) is most known for its role in the metabolic pathway in the tricarboxylic acid cycle or Kreb's Cycle which is critical to cellular respiration in cells [http://en.wikipedia.org/wiki/Citric_acid_cycle]; however, the enzyme is also in many other metabolic pathways such as glyoxylate bypass, amino acid synthesis, glucogenesis, and oxidation/reduction balance <ref>PMID:12537350</ref>. It is classified as a oxidoreductase[http://en.wikipedia.org/wiki/Oxidoreductase]. Malate Dehydrogenase has been extensively studied due to its many isozymes <ref>PMID:20173310</ref>. The enzyme exists in two places inside a cell, in the mitochondria and cytoplasm. In the mitochondria, the enzyme catalyzes the reaction of malate to oxaloacetate; but in the cytoplasm, the enzyme catalyzes oxaloacetate to malate to allow transport <ref>PMID:20173310</ref>. This conversion is an essential catalytic step in each different metabolic mechanism. The enzyme malate dehydrogenase is composed of either a dimer or tetramer depending on the location and organism <ref>PMID: 9834842</ref>. During catalysis, the enzyme subunits are non-cooperative between active sites. The mitochondrial MDH is complexly, allosterically controlled by citrate, but no other known metabolic regulation mechanisms have been discovered. Further, the exact mechanism of regulation has yet to be discovered <ref>PMID:7574693</ref>. Kinetically, the pH of optimization is 7.6 for oxaloacetate conversion and 9.6 for malate conversion. The reported K(m) value for malate conversion is 215 uM and the V(max) value is 87.8 uM/min <ref>PMID:19277715</ref>.{{STRUCTURE_2x0i \| PDB=2x0i \| SCENE= }}

		+	==Structure==
	The secondary structure of a single subunit contains a <scene name='Malate_dehydrogenase/Beta_sheeting_backbone/1'>9 beta sheet parallel backbone</scene> wrapped by <scene name='Malate_dehydrogenase/Alpha_wrapping_betas/1'>9 large alpha helices</scene>. Near the sodium bound end, 4 small anti-parallel beta sheets and 1 small alpha helix enable a turn in the residue chain<scene name='Jake_Ezell_Sandbox_2/Small_turn/1'>(small turn)</scene>. Opposite the sodium bound ligand, 6 alpha helices point towards a common point, three on each side of the beta sheet backbone. The alpha helices form a <scene name='Jake_Ezell_Sandbox_2/Small_groove_nad/1'>small groove</scene> for a NAD+ cofactor to attach near the beta sheeting. The structure most nearly resembles an alternating alpha/beta classification. As for the 3D structure, the enzyme forms a sort of		The secondary structure of a single subunit contains a <scene name='Malate_dehydrogenase/Beta_sheeting_backbone/1'>9 beta sheet parallel backbone</scene> wrapped by <scene name='Malate_dehydrogenase/Alpha_wrapping_betas/1'>9 large alpha helices</scene>. Near the sodium bound end, 4 small anti-parallel beta sheets and 1 small alpha helix enable a turn in the residue chain<scene name='Jake_Ezell_Sandbox_2/Small_turn/1'>(small turn)</scene>. Opposite the sodium bound ligand, 6 alpha helices point towards a common point, three on each side of the beta sheet backbone. The alpha helices form a <scene name='Jake_Ezell_Sandbox_2/Small_groove_nad/1'>small groove</scene> for a NAD+ cofactor to attach near the beta sheeting. The structure most nearly resembles an alternating alpha/beta classification. As for the 3D structure, the enzyme forms a sort of
	<scene name='Jake_Ezell_Sandbox_2/Active_site_no_spin/2'>crevice</scene> for the substrate to bind.		<scene name='Jake_Ezell_Sandbox_2/Active_site_no_spin/2'>crevice</scene> for the substrate to bind.

		+	==Mechanism==
	The mechanism of catalysis is dependent on <scene name='Jake_Ezell_Sandbox_2/Active_site_labeled/2'>several invariant residues</scene>. These residues are HIS 195 and ASP 168 which are involved in hydrogen bonding, ASP 53 associated with <scene name='Jake_Ezell_Sandbox_2/Active_site_labeled_with_nad/1'>NAD+ binding</scene>, and a triad of arginine residues at 102, 109, and 171. During the conversation of malate to oxaloacetate, a key conformational change occurs on the binding of substrate in which a “loop” flips into an up position to block the active site from the solvent.		The mechanism of catalysis is dependent on <scene name='Jake_Ezell_Sandbox_2/Active_site_labeled/2'>several invariant residues</scene>. These residues are HIS 195 and ASP 168 which are involved in hydrogen bonding, ASP 53 associated with <scene name='Jake_Ezell_Sandbox_2/Active_site_labeled_with_nad/1'>NAD+ binding</scene>, and a triad of arginine residues at 102, 109, and 171. During the conversation of malate to oxaloacetate, a key conformational change occurs on the binding of substrate in which a “loop” flips into an up position to block the active site from the solvent.
	[[Image:Malate_Dehydrogenase_Active_Site.JPG\|250 px]] When this occurs, the other residues in the active site are brought closer to the substrate to enable the conversion. R102 and R109 are involved in this loop flip and thus invariant. After the loop flip, the malate complex is stabilized via hydrogen bonding before accepting a proton transfer from NADH to form oxaloacetate <ref>PMID:7849603</ref>.		[[Image:Malate_Dehydrogenase_Active_Site.JPG\|250 px]] When this occurs, the other residues in the active site are brought closer to the substrate to enable the conversion. R102 and R109 are involved in this loop flip and thus invariant. After the loop flip, the malate complex is stabilized via hydrogen bonding before accepting a proton transfer from NADH to form oxaloacetate <ref>PMID:7849603</ref>.

		+	==Evolutionary Divergence==
	The evolutionary past of MDH shows a divergence to form lactate dehydrogenase (LDH) which functions in a very similar way to MDH. Although there is a very low sequence conservation among MDH and LDH’s [http://blast.ncbi.nlm.nih.gov/Blast.cgi] the structure of the enzyme has remained relatively conserved. The key difference between the two is in the substrate: LDH catalyzes pyruvate to lactate.		The evolutionary past of MDH shows a divergence to form lactate dehydrogenase (LDH) which functions in a very similar way to MDH. Although there is a very low sequence conservation among MDH and LDH’s [http://blast.ncbi.nlm.nih.gov/Blast.cgi] the structure of the enzyme has remained relatively conserved. The key difference between the two is in the substrate: LDH catalyzes pyruvate to lactate.

Jake Ezell: /* Malate Dehydrogenase */

Jake Ezell — Mon, 29 Mar 2010 19:26:59 GMT

Malate Dehydrogenase

←Older revision		Revision as of 19:26, 29 March 2010
Line 5:		Line 5:
	<scene name='Jake_Ezell_Sandbox_2/Active_site_no_spin/2'>crevice</scene> for the substrate to bind.		<scene name='Jake_Ezell_Sandbox_2/Active_site_no_spin/2'>crevice</scene> for the substrate to bind.

-	The mechanism of catalysis is dependent on <scene name='Jake_Ezell_Sandbox_2/Active_site_labeled/1'>several invariant residues</scene>. These residues are HIS 195 and ASP 168 which are involved in hydrogen bonding, ASP 53 associated with <scene name='Jake_Ezell_Sandbox_2/Active_site_labeled_with_nad/1'>NAD+ binding</scene>, and a triad of arginine residues at 102, 109, and 171. During the conversation of malate to oxaloacetate, a key conformational change occurs on the binding of substrate in which a “loop” flips into an up position to block the active site from the solvent.	+	The mechanism of catalysis is dependent on <scene name='Jake_Ezell_Sandbox_2/Active_site_labeled/2'>several invariant residues</scene>. These residues are HIS 195 and ASP 168 which are involved in hydrogen bonding, ASP 53 associated with <scene name='Jake_Ezell_Sandbox_2/Active_site_labeled_with_nad/1'>NAD+ binding</scene>, and a triad of arginine residues at 102, 109, and 171. During the conversation of malate to oxaloacetate, a key conformational change occurs on the binding of substrate in which a “loop” flips into an up position to block the active site from the solvent.
	[[Image:Malate_Dehydrogenase_Active_Site.JPG\|250 px]] When this occurs, the other residues in the active site are brought closer to the substrate to enable the conversion. R102 and R109 are involved in this loop flip and thus invariant. After the loop flip, the malate complex is stabilized via hydrogen bonding before accepting a proton transfer from NADH to form oxaloacetate <ref>PMID:7849603</ref>.		[[Image:Malate_Dehydrogenase_Active_Site.JPG\|250 px]] When this occurs, the other residues in the active site are brought closer to the substrate to enable the conversion. R102 and R109 are involved in this loop flip and thus invariant. After the loop flip, the malate complex is stabilized via hydrogen bonding before accepting a proton transfer from NADH to form oxaloacetate <ref>PMID:7849603</ref>.

Jake Ezell: /* Malate Dehydrogenase */

Jake Ezell — Mon, 29 Mar 2010 19:10:19 GMT

Malate Dehydrogenase

←Older revision		Revision as of 19:10, 29 March 2010
Line 1:		Line 1:
	==Malate Dehydrogenase==		==Malate Dehydrogenase==
-	Malate Dehydrogenase (MDH)(PDB entry [http://www.pdb.org/pdb/explore/explore.do?structureId=2X0I 2x0i]) is most known for its role in the metabolic pathway in the tricarboxylic acid cycle[http://en.wikipedia.org/wiki/Citric_acid_cycle]; however, the enzyme is also in many other metabolic pathways such as glyoxylate bypass, amino acid synthesis, glucogenesis, and oxidation/reduction balance <ref>PMID:12537350</ref>. It is classified as a oxidoreductase[http://en.wikipedia.org/wiki/Oxidoreductase]. Malate Dehydrogenase has been extensively studied due to its many isozymes <ref>PMID:20173310</ref>. The enzyme exists in two places inside a cell, in the mitochondria and cytoplasm. In the mitochondria, the enzyme catalyzes the reaction of malate to oxaloacetate; but in the cytoplasm, the enzyme catalyzes oxaloacetate to malate to allow transport <ref>PMID:20173310</ref>. This conversion is an essential catalytic step in each different metabolic mechanism. The enzyme malate dehydrogenase is composed of either a dimer or tetramer <ref>PMID: 9834842</ref>. During catalysis, the enzyme subunits are non-cooperative between active sites. The mitochondrial MDH is complexly, allosterically controlled by citrate, but no other known metabolic regulation mechanisms have been discovered. Further, the exact mechanism of regulation has yet to be discovered <ref>PMID:7574693</ref>. Kinetically, the pH of optimization is 7.6 for oxaloacetate conversion and 9.6 for malate conversion. The reported K(m) value for malate conversion is 215 uM and the V(max) value is 87.8 uM/min <ref>PMID:19277715</ref>.{{STRUCTURE_2x0i \| PDB=2x0i \| SCENE= }}	+	Malate Dehydrogenase (MDH)(PDB entry [http://www.pdb.org/pdb/explore/explore.do?structureId=2X0I 2x0i]) is most known for its role in the metabolic pathway in the tricarboxylic acid cycle or Kreb's Cycle which is critical to cellular respiration in cells [http://en.wikipedia.org/wiki/Citric_acid_cycle]; however, the enzyme is also in many other metabolic pathways such as glyoxylate bypass, amino acid synthesis, glucogenesis, and oxidation/reduction balance <ref>PMID:12537350</ref>. It is classified as a oxidoreductase[http://en.wikipedia.org/wiki/Oxidoreductase]. Malate Dehydrogenase has been extensively studied due to its many isozymes <ref>PMID:20173310</ref>. The enzyme exists in two places inside a cell, in the mitochondria and cytoplasm. In the mitochondria, the enzyme catalyzes the reaction of malate to oxaloacetate; but in the cytoplasm, the enzyme catalyzes oxaloacetate to malate to allow transport <ref>PMID:20173310</ref>. This conversion is an essential catalytic step in each different metabolic mechanism. The enzyme malate dehydrogenase is composed of either a dimer or tetramer depending on the location and organism <ref>PMID: 9834842</ref>. During catalysis, the enzyme subunits are non-cooperative between active sites. The mitochondrial MDH is complexly, allosterically controlled by citrate, but no other known metabolic regulation mechanisms have been discovered. Further, the exact mechanism of regulation has yet to be discovered <ref>PMID:7574693</ref>. Kinetically, the pH of optimization is 7.6 for oxaloacetate conversion and 9.6 for malate conversion. The reported K(m) value for malate conversion is 215 uM and the V(max) value is 87.8 uM/min <ref>PMID:19277715</ref>.{{STRUCTURE_2x0i \| PDB=2x0i \| SCENE= }}

-	The secondary structure of a single subunit contains a <scene name='Malate_dehydrogenase/Beta_sheeting_backbone/1'>9 beta sheet parallel backbone</scene> wrapped by <scene name='Malate_dehydrogenase/Alpha_wrapping_betas/1'>9 large alpha helices</scene>. Near the sodium bound end, 4 small anti-parallel beta sheets and 1 small alpha helix enable a turn in the residue chain<scene name='~~Malate_dehydrogenase~~/Small_turn/1'>(small turn)</scene>. Opposite the sodium bound ligand, 6 alpha helices point towards a common point, three on each side of the beta sheet backbone. The alpha helices form a <scene name='Jake_Ezell_Sandbox_2/Small_groove_nad/1'>small groove</scene> for a NAD+ cofactor to attach near the beta sheeting. The structure most nearly resembles an alternating alpha/beta classification. As for the 3D structure, the enzyme forms a sort of	+	The secondary structure of a single subunit contains a <scene name='Malate_dehydrogenase/Beta_sheeting_backbone/1'>9 beta sheet parallel backbone</scene> wrapped by <scene name='Malate_dehydrogenase/Alpha_wrapping_betas/1'>9 large alpha helices</scene>. Near the sodium bound end, 4 small anti-parallel beta sheets and 1 small alpha helix enable a turn in the residue chain<scene name='Jake_Ezell_Sandbox_2/Small_turn/1'>(small turn)</scene>. Opposite the sodium bound ligand, 6 alpha helices point towards a common point, three on each side of the beta sheet backbone. The alpha helices form a <scene name='Jake_Ezell_Sandbox_2/Small_groove_nad/1'>small groove</scene> for a NAD+ cofactor to attach near the beta sheeting. The structure most nearly resembles an alternating alpha/beta classification. As for the 3D structure, the enzyme forms a sort of
	<scene name='Jake_Ezell_Sandbox_2/Active_site_no_spin/2'>crevice</scene> for the substrate to bind.		<scene name='Jake_Ezell_Sandbox_2/Active_site_no_spin/2'>crevice</scene> for the substrate to bind.

Jake Ezell: /* Malate Dehydrogenase */

Jake Ezell — Mon, 22 Mar 2010 08:09:22 GMT

Malate Dehydrogenase

←Older revision		Revision as of 08:09, 22 March 2010
Line 1:		Line 1:
	==Malate Dehydrogenase==		==Malate Dehydrogenase==
-	Malate Dehydrogenase (MDH)(PDB entry [http://www.pdb.org/pdb/explore/explore.do?structureId=2X0I 2x0i]) is most known for its role in the metabolic pathway in the tricarboxylic acid cycle[http://en.wikipedia.org/wiki/Citric_acid_cycle]; however, the enzyme is also in many other metabolic pathways such as glyoxylate bypass, amino acid synthesis, glucogenesis, and oxidation/reduction balance <ref>PMID:12537350</ref>. It is classified as a oxidoreductase[http://en.wikipedia.org/wiki/Oxidoreductase]. Malate Dehydrogenase has been extensively studied due to its many isozymes <ref>PMID:20173310</ref>. The enzyme exists in two places inside a cell, in the mitochondria and cytoplasm. In the mitochondria, the enzyme catalyzes the reaction of malate to oxaloacetate; but in the cytoplasm, the enzyme catalyzes oxaloacetate to malate to allow transport <ref>PMID:20173310</ref>. This conversion is an essential catalytic step in each different metabolic mechanism. The enzyme malate dehydrogenase is composed of either a dimer or tetramer <ref>PMID: 9834842</ref>. During catalysis, the enzyme subunits are non-cooperative between active sites. The mitochondrial MDH is complexly, allosterically controlled by citrate, but no other known metabolic regulation mechanisms have been discovered. Further, the exact mechanism of regulation has yet to be discovered <ref>PMID:7574693</ref>.{{STRUCTURE_2x0i \| PDB=2x0i \| SCENE= }}	+	Malate Dehydrogenase (MDH)(PDB entry [http://www.pdb.org/pdb/explore/explore.do?structureId=2X0I 2x0i]) is most known for its role in the metabolic pathway in the tricarboxylic acid cycle[http://en.wikipedia.org/wiki/Citric_acid_cycle]; however, the enzyme is also in many other metabolic pathways such as glyoxylate bypass, amino acid synthesis, glucogenesis, and oxidation/reduction balance <ref>PMID:12537350</ref>. It is classified as a oxidoreductase[http://en.wikipedia.org/wiki/Oxidoreductase]. Malate Dehydrogenase has been extensively studied due to its many isozymes <ref>PMID:20173310</ref>. The enzyme exists in two places inside a cell, in the mitochondria and cytoplasm. In the mitochondria, the enzyme catalyzes the reaction of malate to oxaloacetate; but in the cytoplasm, the enzyme catalyzes oxaloacetate to malate to allow transport <ref>PMID:20173310</ref>. This conversion is an essential catalytic step in each different metabolic mechanism. The enzyme malate dehydrogenase is composed of either a dimer or tetramer <ref>PMID: 9834842</ref>. During catalysis, the enzyme subunits are non-cooperative between active sites. The mitochondrial MDH is complexly, allosterically controlled by citrate, but no other known metabolic regulation mechanisms have been discovered. Further, the exact mechanism of regulation has yet to be discovered <ref>PMID:7574693</ref>. Kinetically, the pH of optimization is 7.6 for oxaloacetate conversion and 9.6 for malate conversion. The reported K(m) value for malate conversion is 215 uM and the V(max) value is 87.8 uM/min <ref>PMID:19277715</ref>.{{STRUCTURE_2x0i \| PDB=2x0i \| SCENE= }}

	The secondary structure of a single subunit contains a <scene name='Malate_dehydrogenase/Beta_sheeting_backbone/1'>9 beta sheet parallel backbone</scene> wrapped by <scene name='Malate_dehydrogenase/Alpha_wrapping_betas/1'>9 large alpha helices</scene>. Near the sodium bound end, 4 small anti-parallel beta sheets and 1 small alpha helix enable a turn in the residue chain<scene name='Malate_dehydrogenase/Small_turn/1'>(small turn)</scene>. Opposite the sodium bound ligand, 6 alpha helices point towards a common point, three on each side of the beta sheet backbone. The alpha helices form a <scene name='Jake_Ezell_Sandbox_2/Small_groove_nad/1'>small groove</scene> for a NAD+ cofactor to attach near the beta sheeting. The structure most nearly resembles an alternating alpha/beta classification. As for the 3D structure, the enzyme forms a sort of		The secondary structure of a single subunit contains a <scene name='Malate_dehydrogenase/Beta_sheeting_backbone/1'>9 beta sheet parallel backbone</scene> wrapped by <scene name='Malate_dehydrogenase/Alpha_wrapping_betas/1'>9 large alpha helices</scene>. Near the sodium bound end, 4 small anti-parallel beta sheets and 1 small alpha helix enable a turn in the residue chain<scene name='Malate_dehydrogenase/Small_turn/1'>(small turn)</scene>. Opposite the sodium bound ligand, 6 alpha helices point towards a common point, three on each side of the beta sheet backbone. The alpha helices form a <scene name='Jake_Ezell_Sandbox_2/Small_groove_nad/1'>small groove</scene> for a NAD+ cofactor to attach near the beta sheeting. The structure most nearly resembles an alternating alpha/beta classification. As for the 3D structure, the enzyme forms a sort of

Jake Ezell: /* Malate Dehydrogenase */

Jake Ezell — Mon, 22 Mar 2010 08:02:50 GMT

Malate Dehydrogenase

←Older revision		Revision as of 08:02, 22 March 2010
Line 1:		Line 1:
	==Malate Dehydrogenase==		==Malate Dehydrogenase==
-	Malate Dehydrogenase (MDH)(PDB entry [http://www.pdb.org/pdb/explore/explore.do?structureId=2X0I 2x0i]) is most known for its role in the metabolic pathway in the tricarboxylic acid cycle[http://en.wikipedia.org/wiki/Citric_acid_cycle]; however, the enzyme is also in many other metabolic pathways such as glyoxylate bypass, amino acid synthesis, glucogenesis, and oxidation/reduction balance <ref>PMID:12537350</ref>. It is classified as a oxidoreductase[http://en.wikipedia.org/wiki/Oxidoreductase]. Malate Dehydrogenase has been extensively studied due to its many isozymes <ref>PMID:20173310</ref>. The enzyme exists in two places inside a cell, in the mitochondria and cytoplasm. In the mitochondria, the enzyme catalyzes the reaction of malate to oxaloacetate; but in the cytoplasm, the enzyme catalyzes oxaloacetate to malate to allow transport <ref>PMID:20173310</ref>. This conversion is an essential catalytic step in each different metabolic mechanism. The enzyme malate dehydrogenase is composed of either a dimer or tetramer. During catalysis, the enzyme subunits are non-cooperative between active sites. The mitochondrial MDH is complexly, allosterically controlled by citrate, but no other known metabolic regulation mechanisms have been discovered. Further, the exact mechanism of regulation has yet to be discovered <ref>PMID:7574693</ref>.{{STRUCTURE_2x0i \| PDB=2x0i \| SCENE= }}	+	Malate Dehydrogenase (MDH)(PDB entry [http://www.pdb.org/pdb/explore/explore.do?structureId=2X0I 2x0i]) is most known for its role in the metabolic pathway in the tricarboxylic acid cycle[http://en.wikipedia.org/wiki/Citric_acid_cycle]; however, the enzyme is also in many other metabolic pathways such as glyoxylate bypass, amino acid synthesis, glucogenesis, and oxidation/reduction balance <ref>PMID:12537350</ref>. It is classified as a oxidoreductase[http://en.wikipedia.org/wiki/Oxidoreductase]. Malate Dehydrogenase has been extensively studied due to its many isozymes <ref>PMID:20173310</ref>. The enzyme exists in two places inside a cell, in the mitochondria and cytoplasm. In the mitochondria, the enzyme catalyzes the reaction of malate to oxaloacetate; but in the cytoplasm, the enzyme catalyzes oxaloacetate to malate to allow transport <ref>PMID:20173310</ref>. This conversion is an essential catalytic step in each different metabolic mechanism. The enzyme malate dehydrogenase is composed of either a dimer or tetramer <ref>PMID: 9834842</ref>. During catalysis, the enzyme subunits are non-cooperative between active sites. The mitochondrial MDH is complexly, allosterically controlled by citrate, but no other known metabolic regulation mechanisms have been discovered. Further, the exact mechanism of regulation has yet to be discovered <ref>PMID:7574693</ref>.{{STRUCTURE_2x0i \| PDB=2x0i \| SCENE= }}

	The secondary structure of a single subunit contains a <scene name='Malate_dehydrogenase/Beta_sheeting_backbone/1'>9 beta sheet parallel backbone</scene> wrapped by <scene name='Malate_dehydrogenase/Alpha_wrapping_betas/1'>9 large alpha helices</scene>. Near the sodium bound end, 4 small anti-parallel beta sheets and 1 small alpha helix enable a turn in the residue chain<scene name='Malate_dehydrogenase/Small_turn/1'>(small turn)</scene>. Opposite the sodium bound ligand, 6 alpha helices point towards a common point, three on each side of the beta sheet backbone. The alpha helices form a <scene name='Jake_Ezell_Sandbox_2/Small_groove_nad/1'>small groove</scene> for a NAD+ cofactor to attach near the beta sheeting. The structure most nearly resembles an alternating alpha/beta classification. As for the 3D structure, the enzyme forms a sort of		The secondary structure of a single subunit contains a <scene name='Malate_dehydrogenase/Beta_sheeting_backbone/1'>9 beta sheet parallel backbone</scene> wrapped by <scene name='Malate_dehydrogenase/Alpha_wrapping_betas/1'>9 large alpha helices</scene>. Near the sodium bound end, 4 small anti-parallel beta sheets and 1 small alpha helix enable a turn in the residue chain<scene name='Malate_dehydrogenase/Small_turn/1'>(small turn)</scene>. Opposite the sodium bound ligand, 6 alpha helices point towards a common point, three on each side of the beta sheet backbone. The alpha helices form a <scene name='Jake_Ezell_Sandbox_2/Small_groove_nad/1'>small groove</scene> for a NAD+ cofactor to attach near the beta sheeting. The structure most nearly resembles an alternating alpha/beta classification. As for the 3D structure, the enzyme forms a sort of

Jake Ezell: /* Malate Dehydrogenase */

Jake Ezell — Mon, 22 Mar 2010 08:01:37 GMT

Malate Dehydrogenase

←Older revision		Revision as of 08:01, 22 March 2010
Line 1:		Line 1:
	==Malate Dehydrogenase==		==Malate Dehydrogenase==
-	Malate Dehydrogenase (MDH)(PDB entry [http://www.pdb.org/pdb/explore/explore.do?structureId=2X0I 2x0i]) is most known for its role in the metabolic pathway in the tricarboxylic acid cycle[http://en.wikipedia.org/wiki/Citric_acid_cycle]; however, the enzyme is also in many other metabolic pathways such as glyoxylate bypass, amino acid synthesis, glucogenesis, and oxidation/reduction balance <ref>PMID:12537350</ref>. It is classified as a oxidoreductase[http://en.wikipedia.org/wiki/Oxidoreductase]. Malate Dehydrogenase has been extensively studied due to its many isozymes <ref>PMID:20173310</ref>. The enzyme exists in two places inside a cell, in the mitochondria and cytoplasm. In the mitochondria, the enzyme catalyzes the reaction of malate to oxaloacetate; but in the cytoplasm, the enzyme catalyzes oxaloacetate to malate to allow transport <ref>PMID:20173310</ref>. This conversion is an essential catalytic step in each different metabolic mechanism. The enzyme malate dehydrogenase is composed of either a dimer or tetramer. During catalysis, the enzyme subunits are non-cooperative between active sites. The mitochondrial MDH is allosterically controlled by citrate, but no other known metabolic regulation mechanisms have been discovered.{{STRUCTURE_2x0i \| PDB=2x0i \| SCENE= }}	+	Malate Dehydrogenase (MDH)(PDB entry [http://www.pdb.org/pdb/explore/explore.do?structureId=2X0I 2x0i]) is most known for its role in the metabolic pathway in the tricarboxylic acid cycle[http://en.wikipedia.org/wiki/Citric_acid_cycle]; however, the enzyme is also in many other metabolic pathways such as glyoxylate bypass, amino acid synthesis, glucogenesis, and oxidation/reduction balance <ref>PMID:12537350</ref>. It is classified as a oxidoreductase[http://en.wikipedia.org/wiki/Oxidoreductase]. Malate Dehydrogenase has been extensively studied due to its many isozymes <ref>PMID:20173310</ref>. The enzyme exists in two places inside a cell, in the mitochondria and cytoplasm. In the mitochondria, the enzyme catalyzes the reaction of malate to oxaloacetate; but in the cytoplasm, the enzyme catalyzes oxaloacetate to malate to allow transport <ref>PMID:20173310</ref>. This conversion is an essential catalytic step in each different metabolic mechanism. The enzyme malate dehydrogenase is composed of either a dimer or tetramer. During catalysis, the enzyme subunits are non-cooperative between active sites. The mitochondrial MDH is complexly, allosterically controlled by citrate, but no other known metabolic regulation mechanisms have been discovered. Further, the exact mechanism of regulation has yet to be discovered <ref>PMID:7574693</ref>.{{STRUCTURE_2x0i \| PDB=2x0i \| SCENE= }}

	The secondary structure of a single subunit contains a <scene name='Malate_dehydrogenase/Beta_sheeting_backbone/1'>9 beta sheet parallel backbone</scene> wrapped by <scene name='Malate_dehydrogenase/Alpha_wrapping_betas/1'>9 large alpha helices</scene>. Near the sodium bound end, 4 small anti-parallel beta sheets and 1 small alpha helix enable a turn in the residue chain<scene name='Malate_dehydrogenase/Small_turn/1'>(small turn)</scene>. Opposite the sodium bound ligand, 6 alpha helices point towards a common point, three on each side of the beta sheet backbone. The alpha helices form a <scene name='Jake_Ezell_Sandbox_2/Small_groove_nad/1'>small groove</scene> for a NAD+ cofactor to attach near the beta sheeting. The structure most nearly resembles an alternating alpha/beta classification. As for the 3D structure, the enzyme forms a sort of		The secondary structure of a single subunit contains a <scene name='Malate_dehydrogenase/Beta_sheeting_backbone/1'>9 beta sheet parallel backbone</scene> wrapped by <scene name='Malate_dehydrogenase/Alpha_wrapping_betas/1'>9 large alpha helices</scene>. Near the sodium bound end, 4 small anti-parallel beta sheets and 1 small alpha helix enable a turn in the residue chain<scene name='Malate_dehydrogenase/Small_turn/1'>(small turn)</scene>. Opposite the sodium bound ligand, 6 alpha helices point towards a common point, three on each side of the beta sheet backbone. The alpha helices form a <scene name='Jake_Ezell_Sandbox_2/Small_groove_nad/1'>small groove</scene> for a NAD+ cofactor to attach near the beta sheeting. The structure most nearly resembles an alternating alpha/beta classification. As for the 3D structure, the enzyme forms a sort of

Jake Ezell: /* Malate Dehydrogenase */

Jake Ezell — Mon, 22 Mar 2010 07:58:48 GMT

Malate Dehydrogenase

←Older revision		Revision as of 07:58, 22 March 2010
Line 1:		Line 1:
	==Malate Dehydrogenase==		==Malate Dehydrogenase==
-	Malate Dehydrogenase (MDH)(PDB entry [http://www.pdb.org/pdb/explore/explore.do?structureId=2X0I 2x0i]) is most known for its role in the metabolic pathway in the tricarboxylic acid cycle[http://en.wikipedia.org/wiki/Citric_acid_cycle]; however, the enzyme is also in many other metabolic pathways such as glyoxylate bypass, amino acid synthesis, glucogenesis, and oxidation/reduction balance <ref>PMID:12537350</ref>. It is classified as a oxidoreductase[http://en.wikipedia.org/wiki/Oxidoreductase]. Malate Dehydrogenase has been extensively studied due to its many isozymes <ref>PMID:20173310</ref>. The enzyme exists in two places inside a cell, in the mitochondria and cytoplasm. In the mitochondria, the enzyme catalyzes the reaction of malate to oxaloacetate; but in the cytoplasm, the enzyme catalyzes oxaloacetate to malate to allow transport <ref>PMID:20173310</ref>. This conversion is an essential catalytic step in each different metabolic mechanism. The enzyme malate dehydrogenase is composed of either a dimer or tetramer ~~<ref>PMID:9834842<ref/>~~. During catalysis, the enzyme subunits are non-cooperative between active sites. The mitochondrial MDH is allosterically controlled by citrate, but no other known metabolic regulation mechanisms have been discovered.	+	Malate Dehydrogenase (MDH)(PDB entry [http://www.pdb.org/pdb/explore/explore.do?structureId=2X0I 2x0i]) is most known for its role in the metabolic pathway in the tricarboxylic acid cycle[http://en.wikipedia.org/wiki/Citric_acid_cycle]; however, the enzyme is also in many other metabolic pathways such as glyoxylate bypass, amino acid synthesis, glucogenesis, and oxidation/reduction balance <ref>PMID:12537350</ref>. It is classified as a oxidoreductase[http://en.wikipedia.org/wiki/Oxidoreductase]. Malate Dehydrogenase has been extensively studied due to its many isozymes <ref>PMID:20173310</ref>. The enzyme exists in two places inside a cell, in the mitochondria and cytoplasm. In the mitochondria, the enzyme catalyzes the reaction of malate to oxaloacetate; but in the cytoplasm, the enzyme catalyzes oxaloacetate to malate to allow transport <ref>PMID:20173310</ref>. This conversion is an essential catalytic step in each different metabolic mechanism. The enzyme malate dehydrogenase is composed of either a dimer or tetramer. During catalysis, the enzyme subunits are non-cooperative between active sites. The mitochondrial MDH is allosterically controlled by citrate, but no other known metabolic regulation mechanisms have been discovered.{{STRUCTURE_2x0i \| PDB=2x0i \| SCENE= }}

	The secondary structure of a single subunit contains a <scene name='Malate_dehydrogenase/Beta_sheeting_backbone/1'>9 beta sheet parallel backbone</scene> wrapped by <scene name='Malate_dehydrogenase/Alpha_wrapping_betas/1'>9 large alpha helices</scene>. Near the sodium bound end, 4 small anti-parallel beta sheets and 1 small alpha helix enable a turn in the residue chain<scene name='Malate_dehydrogenase/Small_turn/1'>(small turn)</scene>. Opposite the sodium bound ligand, 6 alpha helices point towards a common point, three on each side of the beta sheet backbone. The alpha helices form a <scene name='Jake_Ezell_Sandbox_2/Small_groove_nad/1'>small groove</scene> for a NAD+ cofactor to attach near the beta sheeting. The structure most nearly resembles an alternating alpha/beta classification. As for the 3D structure, the enzyme forms a sort of		The secondary structure of a single subunit contains a <scene name='Malate_dehydrogenase/Beta_sheeting_backbone/1'>9 beta sheet parallel backbone</scene> wrapped by <scene name='Malate_dehydrogenase/Alpha_wrapping_betas/1'>9 large alpha helices</scene>. Near the sodium bound end, 4 small anti-parallel beta sheets and 1 small alpha helix enable a turn in the residue chain<scene name='Malate_dehydrogenase/Small_turn/1'>(small turn)</scene>. Opposite the sodium bound ligand, 6 alpha helices point towards a common point, three on each side of the beta sheet backbone. The alpha helices form a <scene name='Jake_Ezell_Sandbox_2/Small_groove_nad/1'>small groove</scene> for a NAD+ cofactor to attach near the beta sheeting. The structure most nearly resembles an alternating alpha/beta classification. As for the 3D structure, the enzyme forms a sort of
Line 9:		Line 9:

	The evolutionary past of MDH shows a divergence to form lactate dehydrogenase (LDH) which functions in a very similar way to MDH. Although there is a very low sequence conservation among MDH and LDH’s [http://blast.ncbi.nlm.nih.gov/Blast.cgi] the structure of the enzyme has remained relatively conserved. The key difference between the two is in the substrate: LDH catalyzes pyruvate to lactate.		The evolutionary past of MDH shows a divergence to form lactate dehydrogenase (LDH) which functions in a very similar way to MDH. Although there is a very low sequence conservation among MDH and LDH’s [http://blast.ncbi.nlm.nih.gov/Blast.cgi] the structure of the enzyme has remained relatively conserved. The key difference between the two is in the substrate: LDH catalyzes pyruvate to lactate.
-	{{STRUCTURE_2x0i \| PDB=2x0i \| SCENE= }}

	==References==		==References==

	<references />		<references />

Jake Ezell: /* Malate Dehydrogenase */

Jake Ezell — Mon, 22 Mar 2010 07:56:37 GMT

Malate Dehydrogenase

←Older revision		Revision as of 07:56, 22 March 2010
Line 1:		Line 1:
	==Malate Dehydrogenase==		==Malate Dehydrogenase==
-	Malate Dehydrogenase (MDH)(PDB entry [http://www.pdb.org/pdb/explore/explore.do?structureId=2X0I 2x0i]) is most known for its role in the metabolic pathway in the tricarboxylic acid cycle[http://en.wikipedia.org/wiki/Citric_acid_cycle]; however, the enzyme is also in many other metabolic pathways such as glyoxylate bypass, amino acid synthesis, glucogenesis, and oxidation/reduction balance <ref>PMID:12537350</ref> . It is classified as a oxidoreductase[http://en.wikipedia.org/wiki/Oxidoreductase]. Malate Dehydrogenase has been extensively studied due to its many isozymes <ref>PMID:20173310</ref>. The enzyme exists in two places inside a cell, in the mitochondria and cytoplasm. In the mitochondria, the enzyme catalyzes the reaction of malate to oxaloacetate; but in the cytoplasm, the enzyme catalyzes oxaloacetate to malate to allow transport <ref>PMID:20173310</ref> . This conversion is an essential catalytic step in each different metabolic mechanism. The enzyme malate dehydrogenase is composed of either a dimer or tetramer <ref>PMID: 9834842<ref/> . During catalysis, the enzyme subunits are non-cooperative between active sites. The mitochondrial MDH is allosterically controlled by citrate, but no other known metabolic regulation mechanisms have been discovered.	+	Malate Dehydrogenase (MDH)(PDB entry [http://www.pdb.org/pdb/explore/explore.do?structureId=2X0I 2x0i]) is most known for its role in the metabolic pathway in the tricarboxylic acid cycle[http://en.wikipedia.org/wiki/Citric_acid_cycle]; however, the enzyme is also in many other metabolic pathways such as glyoxylate bypass, amino acid synthesis, glucogenesis, and oxidation/reduction balance <ref>PMID:12537350</ref>. It is classified as a oxidoreductase[http://en.wikipedia.org/wiki/Oxidoreductase]. Malate Dehydrogenase has been extensively studied due to its many isozymes <ref>PMID:20173310</ref>. The enzyme exists in two places inside a cell, in the mitochondria and cytoplasm. In the mitochondria, the enzyme catalyzes the reaction of malate to oxaloacetate; but in the cytoplasm, the enzyme catalyzes oxaloacetate to malate to allow transport <ref>PMID:20173310</ref>. This conversion is an essential catalytic step in each different metabolic mechanism. The enzyme malate dehydrogenase is composed of either a dimer or tetramer <ref>PMID:9834842<ref/>. During catalysis, the enzyme subunits are non-cooperative between active sites. The mitochondrial MDH is allosterically controlled by citrate, but no other known metabolic regulation mechanisms have been discovered.

	The secondary structure of a single subunit contains a <scene name='Malate_dehydrogenase/Beta_sheeting_backbone/1'>9 beta sheet parallel backbone</scene> wrapped by <scene name='Malate_dehydrogenase/Alpha_wrapping_betas/1'>9 large alpha helices</scene>. Near the sodium bound end, 4 small anti-parallel beta sheets and 1 small alpha helix enable a turn in the residue chain<scene name='Malate_dehydrogenase/Small_turn/1'>(small turn)</scene>. Opposite the sodium bound ligand, 6 alpha helices point towards a common point, three on each side of the beta sheet backbone. The alpha helices form a <scene name='Jake_Ezell_Sandbox_2/Small_groove_nad/1'>small groove</scene> for a NAD+ cofactor to attach near the beta sheeting. The structure most nearly resembles an alternating alpha/beta classification. As for the 3D structure, the enzyme forms a sort of		The secondary structure of a single subunit contains a <scene name='Malate_dehydrogenase/Beta_sheeting_backbone/1'>9 beta sheet parallel backbone</scene> wrapped by <scene name='Malate_dehydrogenase/Alpha_wrapping_betas/1'>9 large alpha helices</scene>. Near the sodium bound end, 4 small anti-parallel beta sheets and 1 small alpha helix enable a turn in the residue chain<scene name='Malate_dehydrogenase/Small_turn/1'>(small turn)</scene>. Opposite the sodium bound ligand, 6 alpha helices point towards a common point, three on each side of the beta sheet backbone. The alpha helices form a <scene name='Jake_Ezell_Sandbox_2/Small_groove_nad/1'>small groove</scene> for a NAD+ cofactor to attach near the beta sheeting. The structure most nearly resembles an alternating alpha/beta classification. As for the 3D structure, the enzyme forms a sort of

Jake Ezell: /* Malate Dehydrogenase */

Jake Ezell — Mon, 22 Mar 2010 07:54:22 GMT

Malate Dehydrogenase

←Older revision		Revision as of 07:54, 22 March 2010
Line 1:		Line 1:
	==Malate Dehydrogenase==		==Malate Dehydrogenase==
-	Malate Dehydrogenase (MDH)(PDB entry [http://www.pdb.org/pdb/explore/explore.do?structureId=2X0I 2x0i]) is most known for its role in the metabolic pathway in the tricarboxylic acid cycle[http://en.wikipedia.org/wiki/Citric_acid_cycle]; however, the enzyme is also in many other metabolic pathways such as glyoxylate bypass, amino acid synthesis, glucogenesis, and oxidation/reduction balance <ref>PMID:12537350</ref>. It is classified as a oxidoreductase[http://en.wikipedia.org/wiki/Oxidoreductase]. Malate Dehydrogenase has been extensively studied due to its many isozymes<ref>PMID:20173310</ref>. The enzyme exists in two places inside a cell, in the mitochondria and cytoplasm. In the mitochondria, the enzyme catalyzes the reaction of malate to oxaloacetate; but in the cytoplasm, the enzyme catalyzes oxaloacetate to malate to allow transport <ref>PMID:20173310</ref>. This conversion is an essential catalytic step in each different metabolic mechanism. The enzyme malate dehydrogenase is composed of either a dimer or tetramer <ref>PMID: 9834842<ref/>. During catalysis, the enzyme subunits are non-cooperative between active sites. The mitochondrial MDH is allosterically controlled by citrate, but no other known metabolic regulation mechanisms have been discovered.	+	Malate Dehydrogenase (MDH)(PDB entry [http://www.pdb.org/pdb/explore/explore.do?structureId=2X0I 2x0i]) is most known for its role in the metabolic pathway in the tricarboxylic acid cycle[http://en.wikipedia.org/wiki/Citric_acid_cycle]; however, the enzyme is also in many other metabolic pathways such as glyoxylate bypass, amino acid synthesis, glucogenesis, and oxidation/reduction balance <ref>PMID:12537350</ref> . It is classified as a oxidoreductase[http://en.wikipedia.org/wiki/Oxidoreductase]. Malate Dehydrogenase has been extensively studied due to its many isozymes <ref>PMID:20173310</ref>. The enzyme exists in two places inside a cell, in the mitochondria and cytoplasm. In the mitochondria, the enzyme catalyzes the reaction of malate to oxaloacetate; but in the cytoplasm, the enzyme catalyzes oxaloacetate to malate to allow transport <ref>PMID:20173310</ref> . This conversion is an essential catalytic step in each different metabolic mechanism. The enzyme malate dehydrogenase is composed of either a dimer or tetramer <ref>PMID: 9834842<ref/> . During catalysis, the enzyme subunits are non-cooperative between active sites. The mitochondrial MDH is allosterically controlled by citrate, but no other known metabolic regulation mechanisms have been discovered.

	The secondary structure of a single subunit contains a <scene name='Malate_dehydrogenase/Beta_sheeting_backbone/1'>9 beta sheet parallel backbone</scene> wrapped by <scene name='Malate_dehydrogenase/Alpha_wrapping_betas/1'>9 large alpha helices</scene>. Near the sodium bound end, 4 small anti-parallel beta sheets and 1 small alpha helix enable a turn in the residue chain<scene name='Malate_dehydrogenase/Small_turn/1'>(small turn)</scene>. Opposite the sodium bound ligand, 6 alpha helices point towards a common point, three on each side of the beta sheet backbone. The alpha helices form a <scene name='Jake_Ezell_Sandbox_2/Small_groove_nad/1'>small groove</scene> for a NAD+ cofactor to attach near the beta sheeting. The structure most nearly resembles an alternating alpha/beta classification. As for the 3D structure, the enzyme forms a sort of		The secondary structure of a single subunit contains a <scene name='Malate_dehydrogenase/Beta_sheeting_backbone/1'>9 beta sheet parallel backbone</scene> wrapped by <scene name='Malate_dehydrogenase/Alpha_wrapping_betas/1'>9 large alpha helices</scene>. Near the sodium bound end, 4 small anti-parallel beta sheets and 1 small alpha helix enable a turn in the residue chain<scene name='Malate_dehydrogenase/Small_turn/1'>(small turn)</scene>. Opposite the sodium bound ligand, 6 alpha helices point towards a common point, three on each side of the beta sheet backbone. The alpha helices form a <scene name='Jake_Ezell_Sandbox_2/Small_groove_nad/1'>small groove</scene> for a NAD+ cofactor to attach near the beta sheeting. The structure most nearly resembles an alternating alpha/beta classification. As for the 3D structure, the enzyme forms a sort of

Jake Ezell: /* Jake Ezell Sandbox 1 */

Jake Ezell — Mon, 22 Mar 2010 07:53:20 GMT

Jake Ezell Sandbox 1

←Older revision		Revision as of 07:53, 22 March 2010
Line 1:		Line 1:
-	==~~Jake Ezell Sandbox 1~~==	+	==Malate Dehydrogenase==
-	Malate Dehydrogenase (MDH)(PDB entry [http://www.pdb.org/pdb/explore/explore.do?structureId=2X0I 2x0i]) is most known for its role in the metabolic pathway in the tricarboxylic acid cycle[http://en.wikipedia.org/wiki/Citric_acid_cycle]; however, the enzyme is also in many other metabolic pathways such as glyoxylate bypass, amino acid synthesis, glucogenesis, and oxidation/reduction balance <ref>PMID:12537350</ref>. It is classified as a oxidoreductase[http://en.wikipedia.org/wiki/Oxidoreductase]. Malate Dehydrogenase has been extensively studied due to its many isozymes<ref>PMID:20173310</ref>. The enzyme exists in two places inside a cell, in the mitochondria and cytoplasm. In the mitochondria, the enzyme catalyzes the reaction of malate to oxaloacetate; but in the cytoplasm, the enzyme catalyzes oxaloacetate to malate to allow transport <ref>PMID:20173310</ref>. This conversion is an essential catalytic step in each different metabolic mechanism. The enzyme malate dehydrogenase is composed of either a dimer or tetramer <ref>PMID: 9834842<ref/>. During catalysis, the enzyme subunits are non-cooperative between active sites. The mitochondrial MDH is allosterically controlled by citrate, but no other known metabolic regulation mechanisms have been discovered.~~{{STRUCTURE_2x0i \| PDB=2x0i \| SCENE= }}~~	+	Malate Dehydrogenase (MDH)(PDB entry [http://www.pdb.org/pdb/explore/explore.do?structureId=2X0I 2x0i]) is most known for its role in the metabolic pathway in the tricarboxylic acid cycle[http://en.wikipedia.org/wiki/Citric_acid_cycle]; however, the enzyme is also in many other metabolic pathways such as glyoxylate bypass, amino acid synthesis, glucogenesis, and oxidation/reduction balance <ref>PMID:12537350</ref>. It is classified as a oxidoreductase[http://en.wikipedia.org/wiki/Oxidoreductase]. Malate Dehydrogenase has been extensively studied due to its many isozymes<ref>PMID:20173310</ref>. The enzyme exists in two places inside a cell, in the mitochondria and cytoplasm. In the mitochondria, the enzyme catalyzes the reaction of malate to oxaloacetate; but in the cytoplasm, the enzyme catalyzes oxaloacetate to malate to allow transport <ref>PMID:20173310</ref>. This conversion is an essential catalytic step in each different metabolic mechanism. The enzyme malate dehydrogenase is composed of either a dimer or tetramer <ref>PMID: 9834842<ref/>. During catalysis, the enzyme subunits are non-cooperative between active sites. The mitochondrial MDH is allosterically controlled by citrate, but no other known metabolic regulation mechanisms have been discovered.

	The secondary structure of a single subunit contains a <scene name='Malate_dehydrogenase/Beta_sheeting_backbone/1'>9 beta sheet parallel backbone</scene> wrapped by <scene name='Malate_dehydrogenase/Alpha_wrapping_betas/1'>9 large alpha helices</scene>. Near the sodium bound end, 4 small anti-parallel beta sheets and 1 small alpha helix enable a turn in the residue chain<scene name='Malate_dehydrogenase/Small_turn/1'>(small turn)</scene>. Opposite the sodium bound ligand, 6 alpha helices point towards a common point, three on each side of the beta sheet backbone. The alpha helices form a <scene name='Jake_Ezell_Sandbox_2/Small_groove_nad/1'>small groove</scene> for a NAD+ cofactor to attach near the beta sheeting. The structure most nearly resembles an alternating alpha/beta classification. As for the 3D structure, the enzyme forms a sort of		The secondary structure of a single subunit contains a <scene name='Malate_dehydrogenase/Beta_sheeting_backbone/1'>9 beta sheet parallel backbone</scene> wrapped by <scene name='Malate_dehydrogenase/Alpha_wrapping_betas/1'>9 large alpha helices</scene>. Near the sodium bound end, 4 small anti-parallel beta sheets and 1 small alpha helix enable a turn in the residue chain<scene name='Malate_dehydrogenase/Small_turn/1'>(small turn)</scene>. Opposite the sodium bound ligand, 6 alpha helices point towards a common point, three on each side of the beta sheet backbone. The alpha helices form a <scene name='Jake_Ezell_Sandbox_2/Small_groove_nad/1'>small groove</scene> for a NAD+ cofactor to attach near the beta sheeting. The structure most nearly resembles an alternating alpha/beta classification. As for the 3D structure, the enzyme forms a sort of
Line 8:		Line 8:
	[[Image:Malate_Dehydrogenase_Active_Site.JPG\|250 px]] When this occurs, the other residues in the active site are brought closer to the substrate to enable the conversion. R102 and R109 are involved in this loop flip and thus invariant. After the loop flip, the malate complex is stabilized via hydrogen bonding before accepting a proton transfer from NADH to form oxaloacetate <ref>PMID:7849603</ref>.		[[Image:Malate_Dehydrogenase_Active_Site.JPG\|250 px]] When this occurs, the other residues in the active site are brought closer to the substrate to enable the conversion. R102 and R109 are involved in this loop flip and thus invariant. After the loop flip, the malate complex is stabilized via hydrogen bonding before accepting a proton transfer from NADH to form oxaloacetate <ref>PMID:7849603</ref>.

-	The evolutionary past of MDH shows a divergence to form lactate dehydrogenase (LDH) which functions in a very similar way to MDH. Although there is a very low sequence conservation among MDH and LDH’s [http://blast.ncbi.nlm.nih.gov/Blast.cgi] the structure of the enzyme has remained relatively conserved. The key difference between the two is in the ~~substate~~: LDH catalyzes pyruvate to lactate.	+	The evolutionary past of MDH shows a divergence to form lactate dehydrogenase (LDH) which functions in a very similar way to MDH. Although there is a very low sequence conservation among MDH and LDH’s [http://blast.ncbi.nlm.nih.gov/Blast.cgi] the structure of the enzyme has remained relatively conserved. The key difference between the two is in the substrate: LDH catalyzes pyruvate to lactate.
		+	{{STRUCTURE_2x0i \| PDB=2x0i \| SCENE= }}

	==References==		==References==

	<references />		<references />