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-carboxypeptidase, respectively. The pdcA gene was expressed in Escherichia coli, and the characteristics of the gene product were similar to those of dd-carboxypeptidase (VanY) of vancomycin-resistant enterococci. No apparent changes in cell growth, sporulation, or germination were observed in pdcA deletion mutants.