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1e25
From Proteopedia
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[[Image:1e25.gif|left|200px]] | [[Image:1e25.gif|left|200px]] | ||
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'''THE HIGH RESOLUTION STRUCTURE OF PER-1 CLASS A BETA-LACTAMASE''' | '''THE HIGH RESOLUTION STRUCTURE OF PER-1 CLASS A BETA-LACTAMASE''' | ||
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[[Category: Sougakoff, W.]] | [[Category: Sougakoff, W.]] | ||
[[Category: Tranier, S.]] | [[Category: Tranier, S.]] | ||
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| - | [[Category: | + | [[Category: Class a cephalosporinase]] |
| - | [[Category: | + | [[Category: Hydrolase]] |
| - | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Fri May 2 14:33:53 2008'' | |
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | |
Revision as of 11:33, 2 May 2008
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 Fri May 2 14:33:53 2008
