1iyo

Toho-1 beta-Lactamase In Complex With Cefotaxime

spinqualitylabelsall models 1iyo, resolution 1.80Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1iyo is a 1 chain structure with sequence from Escherichia coli. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.8Å Ligands: CEF, SO4 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function BLT1_ECOLX Has strong cefotaxime-hydrolyzing activity. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed Bacterial resistance to beta-lactam antibiotics is a serious problem limiting current clinical therapy. The most common form of resistance is the production of beta-lactamases that inactivate beta-lactam antibiotics. Toho-1 is an extended-spectrum beta-lactamase that has acquired efficient activity not only to penicillins but also to cephalosporins including the expanded-spectrum cephalosporins that were developed to be stable in former beta-lactamases. We present the acyl-intermediate structures of Toho-1 in complex with cefotaxime (expanded-spectrum cephalosporin), cephalothin (non-expanded-spectrum cephalosporin), and benzylpenicillin at 1.8-, 2.0-, and 2.1-A resolutions, respectively. These structures reveal distinct features that can explain the ability of Toho-1 to hydrolyze expanded-spectrum cephalosporins. First, the Omega-loop of Toho-1 is displaced to avoid the steric contacts with the bulky side chain of cefotaxime. Second, the conserved residues Asn(104) and Asp(240) form unique interactions with the bulky side chain of cefotaxime to fix it tightly. Finally, the unique interaction between the conserved Ser(237) and cephalosporins probably helps to bring the beta-lactam carbonyl group to the suitable position in the oxyanion hole, thus increasing the cephalosporinase activity. Acyl-intermediate structures of the extended-spectrum class A beta-lactamase, Toho-1, in complex with cefotaxime, cephalothin, and benzylpenicillin.,Shimamura T, Ibuka A, Fushinobu S, Wakagi T, Ishiguro M, Ishii Y, Matsuzawa H J Biol Chem. 2002 Nov 29;277(48):46601-8. Epub 2002 Sep 8. PMID:12221102 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Beta-lactamase 3D structures

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