1e25
From Proteopedia
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THE HIGH RESOLUTION STRUCTURE OF PER-1 CLASS A BETA-LACTAMASE
Overview
The treatment of infectious diseases by beta-lactam antibiotics is, continuously challenged by the emergence and dissemination of new, beta-lactamases. In most cases, the cephalosporinase activity of class A, enzymes results from a few mutations in the TEM and SHV penicillinases., The PER-1 beta-lactamase was characterized as a class A enzyme displaying, a cephalosporinase activity. This activity was, however, insensitive to, the mutations of residues known to be critical for providing extended, substrate profiles to TEM and SHV. The x-ray structure of the protein, solved at 1.9-A resolution, reveals that two of the most conserved, features in class A beta-lactamases are not present in this enzyme: the, fold of the Omega-loop and the cis conformation of the peptide bond, between residues 166 and 167. The new fold of the Omega-loop and the, insertion of four residues at the edge of strand S3 generate a broad, cavity that may easily accommodate the bulky substituents of cephalosporin, substrates. The trans conformation of the 166-167 bond is related to the, presence of an aspartic acid at position 136. Selection of class A enzymes, based on the occurrence of both Asp(136) and Asn(179) identifies a, subgroup of enzymes with high sequence homology.
About this Structure
1E25 is a Single protein structure of sequence from Pseudomonas aeruginosa with SO4 as ligand. Active as Beta-lactamase, with EC number 3.5.2.6 Full crystallographic information is available from OCA.
Reference
The high resolution crystal structure for class A beta-lactamase PER-1 reveals the bases for its increase in breadth of activity., Tranier S, Bouthors AT, Maveyraud L, Guillet V, Sougakoff W, Samama JP, J Biol Chem. 2000 Sep 8;275(36):28075-82. PMID:10825176
Page seeded by OCA on Tue Nov 20 13:44:22 2007
