Open AccessCefotaxime‐hydrolysing activity of the β‐lactamase of Klebsiella oxytoca D488 could be related to a threonine residue at position 140
Author(s) -
Reynaud Alain,
Péduzzi Jean,
Barthélémy Michel,
Labia Roger
Publication year - 1991
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1991.tb04744.x
Subject(s) - edman degradation , klebsiella oxytoca , cefotaxime , threonine , biology , trypsin , biochemistry , ceftazidime , protease , residue (chemistry) , beta lactamase inhibitors , microbiology and biotechnology , peptide sequence , enzyme , chemistry , enterobacteriaceae , serine , antibiotics , bacteria , escherichia coli , genetics , gene , pseudomonas aeruginosa
The chromosomally encoded β‐lactamase of Klebsiella oxytoca D483 strain, active against all third‐generation cephalosporins but ceftazidime, was purified to homogeneity. The pure protein was digested by trypsin, Staphylococcus aureus V8 protease or proteinase Asp‐N. Amino acid sequences of the HPLC‐separated proteolytic peptides were determined by manual Edman degradation. Overlapping fragments gave the alignment of the 263 residues of the β‐lactamase which presented 90% homology with the β‐lactamase of the K. oxytoca E23004 strain and about 40% homology with the other enzymes of the structural class A. The cefotaximase activity might result from interaction of a threonine residue at position 140 (position 165 in the numbering of Ambler) with the oxyimino group of the antibiotic.