3OPH

ESBL R164S mutant of SHV-1 beta-lactamase

Summary for 3OPH

• Entry DOI: 10.2210/pdb3oph/pdb
• Related: 1SHV 2H5S 3OPL 3OPP 3OPR
• Descriptor: Beta-lactamase SHV-1, CYCLOHEXYL-HEXYL-BETA-D-MALTOSIDE, 4-(2-HYDROXYETHYL)-1-PIPERAZINE ETHANESULFONIC ACID, ... (4 entities in total)
• Functional Keywords: class a beta-lactamase, hydrolase
• Biological source: Klebsiella pneumoniae
• Total number of polymer chains: 1
• Total formula weight: 32445.38

Authors

Sampson, J.M.,van den Akker, F. (deposition date: 2010-09-01, release date: 2011-07-13, Last modification date: 2023-09-06)

Primary citation

Sampson, J.M.,Ke, W.,Bethel, C.R.,Pagadala, S.R.,Nottingham, M.D.,Bonomo, R.A.,Buynak, J.D.,van den Akker, F.
Ligand-dependent disorder of the Omega loop observed in extended-spectrum SHV-type beta-lactamase.
Antimicrob.Agents Chemother., 55:2303-2309, 2011

PubMed Abstract: Among Gram-negative bacteria, resistance to β-lactams is mediated primarily by β-lactamases (EC 3.2.6.5), periplasmic enzymes that inactivate β-lactam antibiotics. Substitutions at critical amino acid positions in the class A β-lactamase families result in enzymes that can hydrolyze extended-spectrum cephalosporins, thus demonstrating an "extended-spectrum" β-lactamase (ESBL) phenotype. Using SHV ESBLs with substitutions in the Ω loop (R164H and R164S) as target enzymes to understand this enhanced biochemical capability and to serve as a basis for novel β-lactamase inhibitor development, we determined the spectra of activity and crystal structures of these variants. We also studied the inactivation of the R164H and R164S mutants with tazobactam and SA2-13, a unique β-lactamase inhibitor that undergoes a distinctive reaction chemistry in the active site. We noted that the reduced Ki values for the R164H and R164S mutants with SA2-13 are comparable to those with tazobactam (submicromolar). The apo enzyme crystal structures of the R164H and R164S SHV variants revealed an ordered Ω loop architecture that became disordered when SA2-13 was bound. Important structural alterations that result from the binding of SA2-13 explain the enhanced susceptibility of these ESBL enzymes to this inhibitor and highlight ligand-dependent Ω loop flexibility as a mechanism for accommodating and hydrolyzing β-lactam substrates.

PubMed: 21357298
DOI: 10.1128/AAC.01360-10

Experimental method

X-RAY DIFFRACTION (1.34 Å)