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1e25
From Proteopedia
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| , resolution 1.90Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | |||||||
| Gene: | BLAPER-1 (Pseudomonas aeruginosa) | ||||||
| Activity: | Beta-lactamase, with EC number 3.5.2.6 | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
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. 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 Thu Mar 20 10:48:16 2008
