1fqg
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(New page: 200px<br /><applet load="1fqg" size="450" color="white" frame="true" align="right" spinBox="true" caption="1fqg, resolution 1.7Å" /> '''MOLECULAR STRUCTURE O...)
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Revision as of 13:02, 20 November 2007
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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 with PNM as ligand. Active as Beta-lactamase, with EC number 3.5.2.6 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 Tue Nov 20 15:09:46 2007
