Molecular cloning, sequence analysis, and characterization of a penicillin-resistant DD-carboxypeptidase of Myxococcus xanthus

We have cloned a gene, pdcA, from the genomic library of Myxococcus xanthus with an oligonucleotide probe representing conserved regions of penicillin -resistant DD-carboxypeptidases. The amino- and carboxy-terminal halves of the predicted pdcA gene product showed significant sequence similarity to N -acetylmuramoyl-L alanine amidase and penicillin-resistant DD-carboxypeptid ase, respectively. The pdcA gene was expressed in Escherichia coli, and the characteristics of the gene product were similar to those of DD-carboxypep tidase (VanY) of vancomycin-resistant enterococci. No apparent changes in c ell growth, sporulation, or germination were observed in pdcA deletion muta nts.