Open AccessCharacterization of the membrane sensor PenJ for β‐lactam antibodies from Bacillus licheniformis by amino acid substitution
Author(s) -
Takagi Masahiro,
Ohta Toyoo,
Johki Shigeru,
Imanaka Tadayuki
Publication year - 1993
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.1574-6968.1993.tb06306.x
Subject(s) - bacillus licheniformis , mutant , amino acid , biochemistry , binding site , serine , biology , peptide sequence , chemistry , gene , phosphorylation , bacteria , bacillus subtilis , genetics
The PenJ protein of the penicillinase gene ( penP ) expression system from Bacillus licheniformis is an antirepressor and membrane receptor for β‐lactam antibodies. A putative β‐lactam antibiotic binding site including Ser402 and Lys405, which are homologous to the conserved sequence for the β‐lactam binding site (Ser‐X‐X‐Lys) is present. An amino acid substitution was introduced at Ser402 to Ala, removing the hydroxyl group of the serine. The mutant PenJ, S402A, was still functional. However, two other mutants, S402T (Ser402 → Thr) and K405A (Lys405 → Ala), were not functional. Thus, the hydroxyl group of Ser402 does not appear to be important for penicillin binding. Amino acid substitutions (K539R, D591N and K539R · G541V) were introduced in PenJ in the region of the putative phosphoryl binding domain. None of these mutant PenJ proteins was a functional antirepressor. These results suggested that the putative phosphoryl binding domain might be an important region for signal transduction.