3IA2

Pseudomonas fluorescens esterase complexed to the R-enantiomer of a sulfonate transition state analog

3IA2 の概要

• エントリーDOI: 10.2210/pdb3ia2/pdb
• 関連するPDBエントリー: 1va4 3hea
• 分子名称: Arylesterase, (2R)-butane-2-sulfonate, GLYCEROL, ... (5 entities in total)
• 機能のキーワード: alpha-beta hydrolase fold, transition state analog, hydrolase, oxidoreductase, peroxidase
• 由来する生物種: Pseudomonas fluorescens
• タンパク質・核酸の鎖数: 6
• 化学式量合計: 183569.46

構造登録者

Schrag, J.D.,Kazlauskas, R.J.,Jiang, Y.,Morley, K. (登録日: 2009-07-13, 公開日: 2010-07-21, 最終更新日: 2023-09-06)

主引用文献

Jiang, Y.,Morley, K.L.,Schrag, J.D.,Kazlauskas, R.J.
Different active-site loop orientation in serine hydrolases versus acyltransferases.
Chembiochem, 12:768-776, 2011

PubMed Abstract: Acyl transfer is a key reaction in biosynthesis, including synthesis of antibiotics and polyesters. Although researchers have long recognized the similar protein fold and catalytic machinery in acyltransferases and hydrolases, the molecular basis for the different reactivity has been a long-standing mystery. By comparison of X-ray structures, we identified a different oxyanion-loop orientation in the active site. In esterases/lipases a carbonyl oxygen points toward the active site, whereas in acyltransferases a NH of the main-chain amide points toward the active site. Amino acid sequence comparisons alone cannot identify such a difference in the main-chain orientation. To identify how this difference might change the reaction mechanism, we solved the X-ray crystal structure of Pseudomonas fluorescens esterase containing a sulfonate transition-state analogue bound to the active-site serine. This structure mimics the transition state for the attack of water on the acyl-enzyme and shows a bridging water molecule between the carbonyl oxygen mentioned above and the sulfonyl oxygen that mimics the attacking water. A possible mechanistic role for this bridging water molecule is to position and activate the attacking water molecule in hydrolases, but to deactivate the attacking water molecule in acyl transferases.

PubMed: 21351219
DOI: 10.1002/cbic.201000693

実験手法

X-RAY DIFFRACTION (1.65 Å)