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STRUCTURE OF CLASS A CEPHALOSPORINASE FROM PROTEUS VULGARIS K1STRUCTURE OF CLASS A CEPHALOSPORINASE FROM PROTEUS VULGARIS K1
Structural highlights
FunctionBLAB_PROVU Hydrolyzes broad-spectrum beta-lactam antibiotics. Active against cephalosporins such as cefuroxime and cefotaxime. 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 PubMedThe structure of a chromosomal extended-spectrum beta-lactamase (ESBL) having the ability to hydrolyze cephalosporins including cefuroxime and ceftazidime has been determined by X-ray crystallography to 1.75 A resolution. The species-specific class A beta-lactamase from Proteus vulgaris K1 was crystallized at pH 6.25 and its structure solved by molecular replacement. Refinement of the model resulted in crystallographic R and R(free) of 16.9 % and 19.3 %, respectively. The folding of the K1 enzyme is broadly similar to that of non-ESBL TEM-type beta-lactamases (2 A rmsd for C(alpha)) and differs by only 0.35 A for all atoms of six conserved residues in the catalytic site. Other residues promoting extended-spectrum activity in K1 include the side-chains of atypical residues Ser237 and Lys276. These side-chains are linked by two water molecules, one of which lies in the position normally filled by the guanidinium group of Arg244, present in most non-ESBL enzymes but absent from K1. The ammonium group of Lys276, ca 3.5 A from the virtual Arg244 guanidinium position, may interact with polar R2 substitutents on the dihydrothiazene ring of cephalosporins. Structure of an extended-spectrum class A beta-lactamase from Proteus vulgaris K1.,Nukaga M, Mayama K, Crichlow GV, Knox JR J Mol Biol. 2002 Mar 15;317(1):109-17. PMID:11916382[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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