5GMX

Crystal structure of a family VIII carboxylesterase

Summary for 5GMX

• Entry DOI: 10.2210/pdb5gmx/pdb
• Descriptor: Carboxylesterase, phenylmethanesulfonic acid (3 entities in total)
• Functional Keywords: estsrt1, extended spectrum beta-lactamase activity, flexibility, hydrolase
• Biological source: uncultured bacterium
• Total number of polymer chains: 2
• Total formula weight: 87156.72

Authors

An, Y.J.,Cha, S.S. (deposition date: 2016-07-18, release date: 2017-07-26, Last modification date: 2024-10-23)

Primary citation

Cha, S.S.,An, Y.J.
Crystal structure of EstSRT1, a family VIII carboxylesterase displaying hydrolytic activity toward oxyimino cephalosporins
Biochem. Biophys. Res. Commun., 478:818-824, 2016

PubMed Abstract: EstSRT1 is a family VIII carboxylesterase that hydrolyzes oxyimino third- and fourth-generation cephalosporins, first-generation cephalosporins and ester substrates. According to the crystal structure of EstSRT1 (2.0-Å resolution), this protein contains a large α/β domain and a small α-helical domain and harbors three catalytic residues (Ser71, Lys74, and Tyr160) in the cavity at the domain interface, similarly to other family VIII carboxylesterases. Comparison of the structures of EstSRT1 and EstU1, a family VIII carboxylesterase with no hydrolytic activity toward bulky oxyimino cephalosporins, revealed that EstSRT1 has a smaller active site, despite its extended substrate range. The B-factors of the active site segments that could potentially contact with the oxyimino groups and the R2 side chains of oxyimino cephalosporins are higher in EstSRT1 than in EstU1, thus suggesting the role of the active site's structural flexibility in the extension of EstSRT1's substrate spectrum.

PubMed: 27501751
DOI: 10.1016/j.bbrc.2016.08.031

Experimental method

X-RAY DIFFRACTION (2 Å)