Open AccessPenicillin‐binding protein 4 of Escherichia coli shows a novel type of primary structure among penicillin‐interacting proteins
Author(s) -
Mottl H.,
Terpstra P.,
Keck W.
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.tb04445.x
Subject(s) - penicillin binding proteins , amino acid , biochemistry , escherichia coli , peptide sequence , biology , protein primary structure , gene , dna , nucleotide , binding site , nucleic acid sequence , chemistry
Summary The nucleotide sequence of a 1884 bp DNA fragment of E. coli , carrying the gene dacB , was determined. The DNA codes for penicillin‐binding protein 4 (PBP4), an enzyme of 477 amino acids, being involved as a dd ‐carboxypeptidase‐endopeptidase in murein metabolism. The enzyme is translated with a cleavable signal peptide of 20 amino acids, which was verified by sequencing the amino‐terminus of the isolated protein. The characteristic active‐site fingerprints SXXK, SXN and KTG of class A β‐lactamases and penicillin‐binding proteins were located in the sequence. On the basis of amino acid alignments we propose, that PBP4 and class A β‐lactamases share a common evolutionary origin but PBP4 has acquired an additional domain of 188 amino acids in the region between the SXXK and SXN elements.