1piw
From Proteopedia
(New page: 200px<br /><applet load="1piw" size="450" color="white" frame="true" align="right" spinBox="true" caption="1piw, resolution 3.0Å" /> '''APO AND HOLO STRUCTUR...) |
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| - | [[Image:1piw.gif|left|200px]]<br /><applet load="1piw" size=" | + | [[Image:1piw.gif|left|200px]]<br /><applet load="1piw" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1piw, resolution 3.0Å" /> | caption="1piw, resolution 3.0Å" /> | ||
'''APO AND HOLO STRUCTURES OF AN NADP(H)-DEPENDENT CINNAMYL ALCOHOL DEHYDROGENASE FROM SACCHAROMYCES CEREVISIAE'''<br /> | '''APO AND HOLO STRUCTURES OF AN NADP(H)-DEPENDENT CINNAMYL ALCOHOL DEHYDROGENASE FROM SACCHAROMYCES CEREVISIAE'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The crystal structure of Saccharomyces cerevisiae ScAdh6p has been solved | + | The crystal structure of Saccharomyces cerevisiae ScAdh6p has been solved using the anomalous signal from the two zinc atoms found per subunit, and it constitutes the first structure determined from a member of the cinnamyl alcohol dehydrogenase family. ScAdh6p subunits exhibit the general fold of the medium-chain dehydrogenases/reductases (MDR) but with distinct specific characteristics. In the three crystal structures solved (two trigonal and one monoclinic), ScAdh6p molecules appear to be structural heterodimers composed of one subunit in the apo and the second subunit in the holo conformation. Between the two conformations, the relative disposition of domains remains unchanged, while two loops, Cys250-Asn260 and Ile277-Lys292, experience large movements. The apo-apo structure is disfavoured because of steric impairment involving the loop Ile277-Lys292, while in the holo-holo conformation some of the hydrogen bonds between subunits would break apart. These suggest that the first NADPH molecule would bind to the enzyme much more tightly than the second. In addition, fluorimetric analysis of NADPH binding demonstrates that only one cofactor molecule binds per dimer. Therefore, ScAdh6p appears to function according to a half-of-the-sites reactivity mechanism, resulting from a pre-existing (prior to cofactor binding) tendency for the structural asymmetry in the dimer. The specificity of ScAdh6p towards NADPH is mainly due to the tripod-like interactions of the terminal phosphate group with Ser210, Arg211 and Lys215. The size and the shape of the substrate-binding pocket correlate well with the substrate specificity of ScAdh6p towards cinnamaldehyde and other aromatic compounds. The structural relationships of ScAdh6p with other MDR structures are analysed. |
==About this Structure== | ==About this Structure== | ||
| - | 1PIW is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Saccharomyces_cerevisiae Saccharomyces cerevisiae] with ZN and NAP as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http:// | + | 1PIW is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Saccharomyces_cerevisiae Saccharomyces cerevisiae] with <scene name='pdbligand=ZN:'>ZN</scene> and <scene name='pdbligand=NAP:'>NAP</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1PIW OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Saccharomyces cerevisiae]] | [[Category: Saccharomyces cerevisiae]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Biosca, J | + | [[Category: Biosca, J A.]] |
[[Category: Fita, I.]] | [[Category: Fita, I.]] | ||
[[Category: Larroy, C.]] | [[Category: Larroy, C.]] | ||
| - | [[Category: Ochoa, W | + | [[Category: Ochoa, W F.]] |
[[Category: Pares, X.]] | [[Category: Pares, X.]] | ||
[[Category: Valencia, E.]] | [[Category: Valencia, E.]] | ||
| Line 24: | Line 24: | ||
[[Category: nadp(h)dependent]] | [[Category: nadp(h)dependent]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:29:16 2008'' |
Revision as of 12:29, 21 February 2008
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APO AND HOLO STRUCTURES OF AN NADP(H)-DEPENDENT CINNAMYL ALCOHOL DEHYDROGENASE FROM SACCHAROMYCES CEREVISIAE
Overview
The crystal structure of Saccharomyces cerevisiae ScAdh6p has been solved using the anomalous signal from the two zinc atoms found per subunit, and it constitutes the first structure determined from a member of the cinnamyl alcohol dehydrogenase family. ScAdh6p subunits exhibit the general fold of the medium-chain dehydrogenases/reductases (MDR) but with distinct specific characteristics. In the three crystal structures solved (two trigonal and one monoclinic), ScAdh6p molecules appear to be structural heterodimers composed of one subunit in the apo and the second subunit in the holo conformation. Between the two conformations, the relative disposition of domains remains unchanged, while two loops, Cys250-Asn260 and Ile277-Lys292, experience large movements. The apo-apo structure is disfavoured because of steric impairment involving the loop Ile277-Lys292, while in the holo-holo conformation some of the hydrogen bonds between subunits would break apart. These suggest that the first NADPH molecule would bind to the enzyme much more tightly than the second. In addition, fluorimetric analysis of NADPH binding demonstrates that only one cofactor molecule binds per dimer. Therefore, ScAdh6p appears to function according to a half-of-the-sites reactivity mechanism, resulting from a pre-existing (prior to cofactor binding) tendency for the structural asymmetry in the dimer. The specificity of ScAdh6p towards NADPH is mainly due to the tripod-like interactions of the terminal phosphate group with Ser210, Arg211 and Lys215. The size and the shape of the substrate-binding pocket correlate well with the substrate specificity of ScAdh6p towards cinnamaldehyde and other aromatic compounds. The structural relationships of ScAdh6p with other MDR structures are analysed.
About this Structure
1PIW is a Single protein structure of sequence from Saccharomyces cerevisiae with and as ligands. Full crystallographic information is available from OCA.
Reference
Apo and Holo structures of an NADPH-dependent cinnamyl alcohol dehydrogenase from Saccharomyces cerevisiae., Valencia E, Larroy C, Ochoa WF, Pares X, Fita I, Biosca JA, J Mol Biol. 2004 Aug 20;341(4):1049-62. PMID:15289102
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