1fqg
From Proteopedia
MOLECULAR STRUCTURE OF THE ACYL-ENZYME INTERMEDIATE IN TEM-1 BETA-LACTAMASE
Overview
The X-ray crystal structure of the molecular complex of penicillin G with a deacylation-defective mutant of the RTEM-1 beta-lactamase from Escherichia coli shows how these antibiotics are recognized and destroyed. Penicillin G is covalently bound to Ser 70 0 gamma as an acyl-enzyme intermediate. The deduced catalytic mechanism uses Ser 70 0 gamma as the attacking nucleophile during acylation. Lys 73 N zeta acts as a general base in abstracting a proton from Ser 70 and transferring it to the thiazolidine ring nitrogen atom via Ser 130 0 gamma. Deacylation is accomplished by nucleophilic attack on the penicilloyl carbonyl carbon by a water molecule assisted by the general base, Glu 166.
About this Structure
1FQG is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.
Reference
Molecular structure of the acyl-enzyme intermediate in beta-lactam hydrolysis at 1.7 A resolution., Strynadka NC, Adachi H, Jensen SE, Johns K, Sielecki A, Betzel C, Sutoh K, James MN, Nature. 1992 Oct 22;359(6397):700-5. PMID:1436034 Page seeded by OCA on Fri May 2 16:38:44 2008
