2uzz
From Proteopedia
OCA (Talk | contribs)
(New page: 200px<br /><applet load="2uzz" size="350" color="white" frame="true" align="right" spinBox="true" caption="2uzz, resolution 3.20Å" /> '''X-RAY STRUCTURE OF N...)
Next diff →
Revision as of 08:55, 23 January 2008
|
X-RAY STRUCTURE OF N-METHYL-L-TRYPTOPHAN OXIDASE (MTOX)
Overview
The X-ray structure of monomeric N-methyltryptophan oxidase from, Escherichia coli (MTOX) has been solved at 3.2 A resolution by molecular, replacement methods using Bacillus sp. sarcosine oxidase structure (MSOX, 43% sequence identity) as search model. The analysis of the substrate, binding site highlights the structural determinants that favour the, accommodation of the bulky N-methyltryptophan residue in MTOX. In fact, although the nature and geometry of the catalytic residues within the, first contact shell of the FAD moiety appear to be virtually superposable, in MTOX and MSOX, the presence of a Thr residue in position 239 in MTOX, (Met245 in MSOX) located at the entrance of the active site appears to, play a key role for the recognition of the amino acid substrate side, chain. Accordingly, a 15 fold increase in k(cat) and 100 fold decrease in, K(m) for sarcosine as substrate has been achieved in MTOX upon T239M, mutation, with a concomitant three-fold decrease in activity towards, N-methyltryptophan. These data provide clear evidence for the presence of, a catalytic core, common to the members of the methylaminoacid oxidase, subfamily, and of a side chain recognition pocket, located at the entrance, of the active site, that can be adjusted to host diverse aminoacids in the, different enzyme species. The site involved in the covalent attachment of, flavin has also been addressed by screening degenerate mutants in the, relevant positions around Cys308-FAD linkage. Lys341 appears to be the key, residue involved in flavin incorporation and covalent linkage. Proteins, 2008. (c) 2008 Wiley-Liss, Inc.
About this Structure
2UZZ is a Single protein structure of sequence from Escherichia coli with and as ligands. Known structural/functional Sites: , , , , , , and . Full crystallographic information is available from OCA.
Reference
The X-ray structure of N-methyltryptophan oxidase reveals the structural determinants of substrate specificity., Ilari A, Bonamore A, Franceschini S, Fiorillo A, Boffi A, Colotti G, Proteins. 2008 Jan 10;. PMID:18186483
Page seeded by OCA on Wed Jan 23 10:55:48 2008
