1khh
From Proteopedia
(New page: 200px<br /><applet load="1khh" size="450" color="white" frame="true" align="right" spinBox="true" caption="1khh, resolution 2.5Å" /> '''Crystal Structure of ...) |
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| - | [[Image:1khh.gif|left|200px]]<br /><applet load="1khh" size=" | + | [[Image:1khh.gif|left|200px]]<br /><applet load="1khh" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1khh, resolution 2.5Å" /> | caption="1khh, resolution 2.5Å" /> | ||
'''Crystal Structure of Guanidinoacetate Methyltransferase from Rat Liver: A Template Structure of Protein Arginine Methyltransferase'''<br /> | '''Crystal Structure of Guanidinoacetate Methyltransferase from Rat Liver: A Template Structure of Protein Arginine Methyltransferase'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Guanidinoacetate methyltransferase (GAMT) is the enzyme that catalyzes the | + | Guanidinoacetate methyltransferase (GAMT) is the enzyme that catalyzes the last step of creatine biosynthesis. The enzyme is found in abundance in the livers of all vertebrates. Recombinant rat liver GAMT has been crystallized with S-adenosylhomocysteine (SAH), and the crystal structure has been determined at 2.5 A resolution. The 36 amino acid residues at the N terminus were cleaved during the purification and the truncated enzyme was crystallized. The truncated enzyme forms a dimer, and each subunit contains one SAH molecule in the active site. Arg220 of the partner subunit forms a pair of hydrogen bonds with Asp134 at the guanidinoacetate-binding site. On the basis of the crystal structure, site-directed mutagenesis on Asp134, and chemical modification and limited proteolysis studies, we propose a catalytic mechanism of this enzyme. The truncated GAMT dimer structure can be seen as a ternary complex of protein arginine methyltransferase (one subunit) complexed with a protein substrate (the partner subunit) and the product SAH. Therefore, this structure provides insight into the structure and catalysis of protein arginine methyltransferases. |
==About this Structure== | ==About this Structure== | ||
| - | 1KHH is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Rattus_norvegicus Rattus norvegicus] with SAH as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Guanidinoacetate_N-methyltransferase Guanidinoacetate N-methyltransferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.1.1.2 2.1.1.2] Full crystallographic information is available from [http:// | + | 1KHH is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Rattus_norvegicus Rattus norvegicus] with <scene name='pdbligand=SAH:'>SAH</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Guanidinoacetate_N-methyltransferase Guanidinoacetate N-methyltransferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.1.1.2 2.1.1.2] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1KHH OCA]. |
==Reference== | ==Reference== | ||
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[[Category: methyltransferase]] | [[Category: methyltransferase]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:34:16 2008'' |
Revision as of 11:34, 21 February 2008
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Crystal Structure of Guanidinoacetate Methyltransferase from Rat Liver: A Template Structure of Protein Arginine Methyltransferase
Overview
Guanidinoacetate methyltransferase (GAMT) is the enzyme that catalyzes the last step of creatine biosynthesis. The enzyme is found in abundance in the livers of all vertebrates. Recombinant rat liver GAMT has been crystallized with S-adenosylhomocysteine (SAH), and the crystal structure has been determined at 2.5 A resolution. The 36 amino acid residues at the N terminus were cleaved during the purification and the truncated enzyme was crystallized. The truncated enzyme forms a dimer, and each subunit contains one SAH molecule in the active site. Arg220 of the partner subunit forms a pair of hydrogen bonds with Asp134 at the guanidinoacetate-binding site. On the basis of the crystal structure, site-directed mutagenesis on Asp134, and chemical modification and limited proteolysis studies, we propose a catalytic mechanism of this enzyme. The truncated GAMT dimer structure can be seen as a ternary complex of protein arginine methyltransferase (one subunit) complexed with a protein substrate (the partner subunit) and the product SAH. Therefore, this structure provides insight into the structure and catalysis of protein arginine methyltransferases.
About this Structure
1KHH is a Single protein structure of sequence from Rattus norvegicus with as ligand. Active as Guanidinoacetate N-methyltransferase, with EC number 2.1.1.2 Full crystallographic information is available from OCA.
Reference
Crystal structure of guanidinoacetate methyltransferase from rat liver: a model structure of protein arginine methyltransferase., Komoto J, Huang Y, Takata Y, Yamada T, Konishi K, Ogawa H, Gomi T, Fujioka M, Takusagawa F, J Mol Biol. 2002 Jul 5;320(2):223-35. PMID:12079381
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