3A3X

Structure of OpdA mutant (G60A/A80V/R118Q/K185R/Q206P/D208G/I260T/G273S)

3A3X の概要

• エントリーDOI: 10.2210/pdb3a3x/pdb
• 関連するPDBエントリー: 3A3W
• 分子名称: Phosphotriesterase, COBALT (II) ION (3 entities in total)
• 機能のキーワード: phosphotriesterase, opda, metalloenzyme, hydrolase
• 由来する生物種: Agrobacterium tumefaciens
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 35761.45

構造登録者

Ollis, D.L.,Tawfik, D.S.,Schenk, G.,Jackson, C.J.,Foo, J.L.,Tokuriki, N.,Afriat, L.,Carr, P.D.,Kim, H.K. (登録日: 2009-06-23, 公開日: 2010-01-12, 最終更新日: 2023-11-15)

主引用文献

Jackson, C.J.,Foo, J.-L.,Tokuriki, N.,Afriat, L.,Carr, P.D.,Kim, H.-K.,Schenk, G.,Tawfik, D.S.,Ollis, D.L.
Conformational sampling, catalysis, and evolution of the bacterial phosphotriesterase
Proc.Natl.Acad.Sci.USA, 2009

PubMed Abstract: To efficiently catalyze a chemical reaction, enzymes are required to maintain fast rates for formation of the Michaelis complex, the chemical reaction and product release. These distinct demands could be satisfied via fluctuation between different conformational substates (CSs) with unique configurations and catalytic properties. However, there is debate as to how these rapid conformational changes, or dynamics, exactly affect catalysis. As a model system, we have studied bacterial phosphotriesterase (PTE), which catalyzes the hydrolysis of the pesticide paraoxon at rates limited by a physical barrier-either substrate diffusion or conformational change. The mechanism of paraoxon hydrolysis is understood in detail and is based on a single, dominant, enzyme conformation. However, the other aspects of substrate turnover (substrate binding and product release), although possibly rate-limiting, have received relatively little attention. This work identifies "open" and "closed" CSs in PTE and dominant structural transition in the enzyme that links them. The closed state is optimally preorganized for paraoxon hydrolysis, but seems to block access to/from the active site. In contrast, the open CS enables access to the active site but is poorly organized for hydrolysis. Analysis of the structural and kinetic effects of mutations distant from the active site suggests that remote mutations affect the turnover rate by altering the conformational landscape.

PubMed: 19966226
DOI: 10.1073/pnas.0907548106

実験手法

X-RAY DIFFRACTION (1.7 Å)