1TQH

Covalent Reaction intermediate Revealed in Crystal Structure of the Geobacillus stearothermophilus Carboxylesterase Est30

Summary for 1TQH

• Entry DOI: 10.2210/pdb1tqh/pdb
• Descriptor: Carboxylesterase precursor, SULFATE ION, PROPYL ACETATE, ... (4 entities in total)
• Functional Keywords: carboxylesterase, tetrahedral intermediate, alpha/beta hydrolase, hydrolase
• Biological source: Geobacillus stearothermophilus
• Total number of polymer chains: 1
• Total formula weight: 28715.73

Authors

Liu, P.,Wang, Y.F.,Ewis, H.E.,Abdelal, A.T.,Lu, C.D.,Harrison, R.W.,Weber, I.T. (deposition date: 2004-06-17, release date: 2004-09-28, Last modification date: 2024-11-06)

Primary citation

Liu, P.,Wang, Y.F.,Ewis, H.E.,Abdelal, A.T.,Lu, C.D.,Harrison, R.W.,Weber, I.T.
Covalent reaction intermediate revealed in crystal structure of the Geobacillus stearothermophilus carboxylesterase Est30.
J.Mol.Biol., 342:551-561, 2004

PubMed Abstract: 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.

PubMed: 15327954
DOI: 10.1016/j.jmb.2004.06.069

Experimental method

X-RAY DIFFRACTION (1.63 Å)