2uyb
From Proteopedia
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S161A MUTANT OF BACILLUS SUBTILIS OXALATE DECARBOXYLASE OXDC
Overview
Oxalate decarboxylase (EC 4.1.1.2) catalyses the conversion of oxalate to, carbon dioxide and formate. It requires manganese and, uniquely, dioxygen, for catalysis. It forms a homohexamer and each subunit contains two, similar, but distinct, manganese sites termed sites 1 and 2. There is, kinetic evidence that only site 1 is catalytically active and that site 2, is purely structural. However, the kinetics of enzymes with mutations in, site 2 are often ambiguous and all mutant kinetics have been interpreted, without structural information. Nine new site-directed mutants have been, generated and four mutant crystal structures have now been solved. Most, mutants targeted either the flexibility (T165P), favoured conformation, (S161A, S164A, D297A or H299A) or presence (Delta162-3 or Delta162-4) of a, lid associated with site 1. The kinetics of these mutants were consistent, with only site 1 being catalytically active. This was particularly, striking with D297A and H299A because they disrupted hydrogen bonds, between the lid and a neighbouring subunit only when in the open, conformation and were distant from site 2. These observations also, provided the first evidence that the flexibility and stability of lid, conformations are important in catalysis. The deletion of the lid to mimic, the plant oxalate oxidase led to a loss of decarboxylase activity, but, only a slight elevation in the oxalate oxidase side reaction, implying, other changes are required to afford a reaction specificity switch. The, four mutant crystal structures (R92A, E162A, Delta162-3 and S161A), strongly support the hypothesis that site 2 is purely structural.
About this Structure
2UYB is a Single protein structure of sequence from Bacillus subtilis with , and as ligands. Active as Oxalate decarboxylase, with EC number 4.1.1.2 Known structural/functional Site: . Full crystallographic information is available from OCA.
Reference
The identity of the active site of oxalate decarboxylase and the importance of the stability of active site lid conformations., Just VJ, Burrell MR, Bowater L, McRobbie I, Stevenson CE, Lawson DM, Bornemann S, Biochem J. 2007 Aug 6;. PMID:17680775
Page seeded by OCA on Sun Feb 3 10:48:22 2008
Categories: Bacillus subtilis | Oxalate decarboxylase | Single protein | Bornemann, S. | Bowater, L. | Burrell, M.R. | Just, V.J. | Lawson, D.M. | Mcrobbie, I. | Stevenson, C.E.M. | FMT | MN | TRS | Cupin | Decarboxylase | Formate | Lyase | Manganese | Metal binding protein | Metal-binding | Oxalate | S161a mutant
