5JIB

Crystal structure of the Thermotoga maritima acetyl esterase (TM0077) complex with a substrate analog

5JIB の概要

• エントリーDOI: 10.2210/pdb5jib/pdb
• 関連するPDBエントリー: 3m82 3m83 5FDF 5HFN
• 分子名称: Cephalosporin-C deacetylase, [(3S)-2-oxo-2,3-dihydro-1H-indol-3-yl]acetic acid (3 entities in total)
• 機能のキーワード: hydrolase, carbohydrate metabolism, cephalosporin deacetylase, rossmann fold
• 由来する生物種: Thermotoga maritima (strain ATCC 43589 / MSB8 / DSM 3109 / JCM 10099)
• 細胞内の位置: Cytoplasm : Q9WXT2
• タンパク質・核酸の鎖数: 6
• 化学式量合計: 233124.63

構造登録者

Manoj, N. (登録日: 2016-04-22, 公開日: 2017-03-01, 最終更新日: 2023-11-08)

主引用文献

Singh, M.K.,Manoj, N.
Crystal structure of Thermotoga maritima acetyl esterase complex with a substrate analog: Insights into the distinctive substrate specificity in the CE7 carbohydrate esterase family
Biochem. Biophys. Res. Commun., 476:63-68, 2016

PubMed Abstract: The carbohydrate esterase family 7 (CE7) members are acetyl esterases that possess unusual substrate specificity for cephalosporin C and 7-amino-cephalosporanic acid. This family containing the α/β hydrolase fold has a distinctive substrate profile that allows it to carry out hydrolysis of esters containing diverse alcohol moieties while maintaining narrow specificity for an acetate ester. Here we investigate the structural basis of this preference for small acyl groups using the crystal structure of the thermostable Thermotoga maritima CE7 acetyl esterase (TmAcE) complexed with a non-cognate substrate analog. The structure determined at 1.86 Å resolution provides direct evidence for the location of the largely hydrophobic and rigid substrate binding pocket in this family. Furthermore, a three-helix insertion domain near the catalytic machinery shapes the substrate binding site. The structure reveals two residues (Pro228 and Ile276) which constitute a hydrophobic rigid binding surface for the acyl group of the ester and thus restricts the size of the acyl group that be accommodated. In combination with previous literature on kinetic properties of the enzyme, our studies suggest that these residues determine the unique specificity of the TmAcE for short straight chain esters. The structure provides a template for focused attempts to engineer the CE7 enzymes for enhanced stability, selectivity or activity for biocatalytic applications.

PubMed: 27181355
DOI: 10.1016/j.bbrc.2016.05.061

実験手法

X-RAY DIFFRACTION (1.86 Å)