1tqh
Covalent Reaction intermediate Revealed in Crystal Structure of the Geobacillus stearothermophilus Carboxylesterase Est30
OverviewOverview
Est30 is a thermophilic carboxylesterase cloned from Geobacillus stearothermophilus that showed optimal hydrolysis of esters with short acyl chains at 70 degrees C. Est30 is a member of a new family of carboxylesterases with representatives in other Gram-positive bacteria. The crystal structure has been determined at 1.63A resolution using multiple anomalous dispersion data. The two-domain crystal structure showed a large domain with a modified alpha/beta hydrolase core including a seven, rather than an eight-stranded beta sheet, and a smaller cap domain comprising three alpha helices. The catalytic triad consists of residues Ser94, Asp193, and His223. A 100Da tetrahedral ligand was observed to be covalently bound to the side-chain of Ser94. The propyl acetate ligand represents the first tetrahedral intermediate in the reaction mechanism. Therefore, this Est30 crystal structure will help understand the mode of action of all enzymes in the serine hydrolase superfamily.
About this StructureAbout this Structure
1TQH is a Single protein structure of sequence from Geobacillus stearothermophilus. Full crystallographic information is available from OCA.
ReferenceReference
Covalent reaction intermediate revealed in crystal structure of the Geobacillus stearothermophilus carboxylesterase Est30., Liu P, Wang YF, Ewis HE, Abdelal AT, Lu CD, Harrison RW, Weber IT, J Mol Biol. 2004 Sep 10;342(2):551-61. PMID:15327954 Page seeded by OCA on Sat May 3 10:15:21 2008