1bxz
From Proteopedia
(New page: 200px<br /><applet load="1bxz" size="450" color="white" frame="true" align="right" spinBox="true" caption="1bxz, resolution 2.99Å" /> '''CRYSTAL STRUCTURE OF...) |
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| - | [[Image:1bxz.gif|left|200px]]<br /><applet load="1bxz" size=" | + | [[Image:1bxz.gif|left|200px]]<br /><applet load="1bxz" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1bxz, resolution 2.99Å" /> | caption="1bxz, resolution 2.99Å" /> | ||
'''CRYSTAL STRUCTURE OF A THERMOPHILIC ALCOHOL DEHYDROGENASE SUBSTRATE COMPLEX FROM THERMOANAEROBACTER BROCKII'''<br /> | '''CRYSTAL STRUCTURE OF A THERMOPHILIC ALCOHOL DEHYDROGENASE SUBSTRATE COMPLEX FROM THERMOANAEROBACTER BROCKII'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The crystal structure of a thermophilic alcohol dehydrogenase (TBAD) from | + | The crystal structure of a thermophilic alcohol dehydrogenase (TBAD) from Thermoanaerobacter brockii has been determined in a binary complex with sec-butanol as substrate to a resolution of 3.0 A. Van der Waals interactions of the carbon C1 atom of sec-butanol with atoms in His59, Ala85, Trp110, Asp150, and Leu294 account for the substrate preference of this enzyme for secondary over primary alcohols. A crevice from the surface to the active site provides access for substrates and products. This opening is lined with the hydrophobic residues Ile49, Leu107, Trp110, Tyr267, Leu294 as well as Cys283 and Met285 from another molecule within the tetrameric assembly. This might explain the tolerance of this enzyme toward organic solvents. The zinc ion occupies a position in the active site, which is too remote for direct interaction with the alcohol group. A mechanism is suggested whereby the introduction of NADP would trigger a displacement of the zinc ion to its catalytic site. Features important for the unusually high melting temperature of 98 degrees C are suggested by comparison to the crystal structure of a highly homologous mesophilic alcohol dehydrogenase from Clostridium beijerinckii (CBAD). The thermophilic enzyme has a more hydrophilic exterior, a more hydrophobic interior, a smaller surface area, more prolines, alanines, and fewer serines than CBAD. Furthermore, in the thermophilic enzyme the number of all types of intersubunit interactions in these tetrameric enzymes is increased: more salt bridges, hydrogen bonds, and hydrophobic interactions. All these effects combined can account for the higher melting temperature of the thermophilic enzyme. |
==About this Structure== | ==About this Structure== | ||
| - | 1BXZ is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Thermoanaerobacter_brockii Thermoanaerobacter brockii] with ZN, CL, MG and SBT as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Alcohol_dehydrogenase_(NADP(+)) Alcohol dehydrogenase (NADP(+))], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.1.1.2 1.1.1.2] Full crystallographic information is available from [http:// | + | 1BXZ is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Thermoanaerobacter_brockii Thermoanaerobacter brockii] with <scene name='pdbligand=ZN:'>ZN</scene>, <scene name='pdbligand=CL:'>CL</scene>, <scene name='pdbligand=MG:'>MG</scene> and <scene name='pdbligand=SBT:'>SBT</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Alcohol_dehydrogenase_(NADP(+)) Alcohol dehydrogenase (NADP(+))], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.1.1.2 1.1.1.2] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1BXZ OCA]. |
==Reference== | ==Reference== | ||
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[[Category: thermophilic alcohol dehydrogenase]] | [[Category: thermophilic alcohol dehydrogenase]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:00:18 2008'' |
Revision as of 10:00, 21 February 2008
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CRYSTAL STRUCTURE OF A THERMOPHILIC ALCOHOL DEHYDROGENASE SUBSTRATE COMPLEX FROM THERMOANAEROBACTER BROCKII
Overview
The crystal structure of a thermophilic alcohol dehydrogenase (TBAD) from Thermoanaerobacter brockii has been determined in a binary complex with sec-butanol as substrate to a resolution of 3.0 A. Van der Waals interactions of the carbon C1 atom of sec-butanol with atoms in His59, Ala85, Trp110, Asp150, and Leu294 account for the substrate preference of this enzyme for secondary over primary alcohols. A crevice from the surface to the active site provides access for substrates and products. This opening is lined with the hydrophobic residues Ile49, Leu107, Trp110, Tyr267, Leu294 as well as Cys283 and Met285 from another molecule within the tetrameric assembly. This might explain the tolerance of this enzyme toward organic solvents. The zinc ion occupies a position in the active site, which is too remote for direct interaction with the alcohol group. A mechanism is suggested whereby the introduction of NADP would trigger a displacement of the zinc ion to its catalytic site. Features important for the unusually high melting temperature of 98 degrees C are suggested by comparison to the crystal structure of a highly homologous mesophilic alcohol dehydrogenase from Clostridium beijerinckii (CBAD). The thermophilic enzyme has a more hydrophilic exterior, a more hydrophobic interior, a smaller surface area, more prolines, alanines, and fewer serines than CBAD. Furthermore, in the thermophilic enzyme the number of all types of intersubunit interactions in these tetrameric enzymes is increased: more salt bridges, hydrogen bonds, and hydrophobic interactions. All these effects combined can account for the higher melting temperature of the thermophilic enzyme.
About this Structure
1BXZ is a Single protein structure of sequence from Thermoanaerobacter brockii with , , and as ligands. Active as Alcohol dehydrogenase (NADP(+)), with EC number 1.1.1.2 Full crystallographic information is available from OCA.
Reference
Crystal structure of a thermophilic alcohol dehydrogenase substrate complex suggests determinants of substrate specificity and thermostability., Li C, Heatwole J, Soelaiman S, Shoham M, Proteins. 1999 Dec 1;37(4):619-27. PMID:10651277
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