From Proteopedia
(Difference between revisions)
proteopedia linkproteopedia link
|
|
| Line 1: |
Line 1: |
| - | [[Image:2nxw.jpg|left|200px]] | + | {{Seed}} |
| | + | [[Image:2nxw.png|left|200px]] |
| | | | |
| | <!-- | | <!-- |
| Line 9: |
Line 10: |
| | {{STRUCTURE_2nxw| PDB=2nxw | SCENE= }} | | {{STRUCTURE_2nxw| PDB=2nxw | SCENE= }} |
| | | | |
| - | '''Crystal structure of phenylpyruvate decarboxylase of Azospirillum brasilense'''
| + | ===Crystal structure of phenylpyruvate decarboxylase of Azospirillum brasilense=== |
| | | | |
| | | | |
| - | ==Overview==
| + | <!-- |
| - | Phenylpyruvate decarboxylase (PPDC) of Azospirillum brasilense, involved in the biosynthesis of the plant hormone indole-3-acetic acid and the antimicrobial compound phenylacetic acid, is a thiamine diphosphate-dependent enzyme that catalyses the nonoxidative decarboxylation of indole- and phenylpyruvate. Analogous to yeast pyruvate decarboxylases, PPDC is subject to allosteric substrate activation, showing sigmoidal v versus [S] plots. The present paper reports the crystal structure of this enzyme determined at 1.5 A resolution. The subunit architecture of PPDC is characteristic for other members of the pyruvate oxidase family, with each subunit consisting of three domains with an open alpha/beta topology. An active site loop, bearing the catalytic residues His112 and His113, could not be modelled due to flexibility. The biological tetramer is best described as an asymmetric dimer of dimers. A cysteine residue that has been suggested as the site for regulatory substrate binding in yeast pyruvate decarboxylase is not conserved, requiring a different mechanism for allosteric substrate activation in PPDC. Only minor changes occur in the interactions with the cofactors, thiamine diphosphate and Mg2+, compared to pyruvate decarboxylase. A greater diversity is observed in the substrate binding pocket accounting for the difference in substrate specificity. Moreover, a catalytically important glutamate residue conserved in nearly all decarboxylases is replaced by a leucine in PPDC. The consequences of these differences in terms of the catalytic and regulatory mechanism of PPDC are discussed.
| + | The line below this paragraph, {{ABSTRACT_PUBMED_17403037}}, adds the Publication Abstract to the page |
| | + | (as it appears on PubMed at http://www.pubmed.gov), where 17403037 is the PubMed ID number. |
| | + | --> |
| | + | {{ABSTRACT_PUBMED_17403037}} |
| | | | |
| | ==About this Structure== | | ==About this Structure== |
| Line 30: |
Line 34: |
| | [[Category: Open active site loop]] | | [[Category: Open active site loop]] |
| | [[Category: Thiamine pyrophosphate]] | | [[Category: Thiamine pyrophosphate]] |
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun May 4 10:03:08 2008'' | + | |
| | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Mon Jul 28 04:59:51 2008'' |
Revision as of 01:59, 28 July 2008
Template:STRUCTURE 2nxw
Crystal structure of phenylpyruvate decarboxylase of Azospirillum brasilense
Template:ABSTRACT PUBMED 17403037
About this Structure
2NXW is a Single protein structure of sequence from Azospirillum brasilense. Full crystallographic information is available from OCA.
Reference
The crystal structure of phenylpyruvate decarboxylase from Azospirillum brasilense at 1.5 A resolution. Implications for its catalytic and regulatory mechanism., Versees W, Spaepen S, Vanderleyden J, Steyaert J, FEBS J. 2007 May;274(9):2363-75. Epub 2007 Mar 30. PMID:17403037
Page seeded by OCA on Mon Jul 28 04:59:51 2008
