title: Identification of MpaA, an amidase in Escherichia coli that hydrolyzes the gamma-D-glutamyl-meso-diaminopimelate bond in murein peptides.
abstract: MpaA amidase was identified in Escherichia coli by its amino acid sequence homology with the ENP1 endopeptidase from Bacillus sphaericus. The enzymatic activity of MpaA, i.e., hydrolysis of the gamma-D-glutamyl-diaminopimelic acid bond in the murein tripeptide L-alanyl-gamma-D-glutamyl-meso-diaminopimelic acid, was demonstrated in the cell extract of a strain expressing mpaA from a multicopy plasmid. An mpaA mpl (murein peptide ligase) double mutant accumulated large amounts of murein tripeptide in its cytoplasm, consistent with the premise that MpaA degrades the tripeptide if its recycling via the peptidoglycan biosynthetic pathway is blocked.
authors.affiliation: Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts 02111, USA.
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Uehara
authors.forename: James T
authors.initials: JT
authors.lastname: Park
mesh_terms: D000581:Amidohydrolases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D000595:Amino Acid Sequence; D001407:Bacillus / Q000201:enzymology; D003960:Diaminopimelic Acid / Q000737:chemistry / Q000378:metabolism*; D010450:Endopeptidases / Q000737:chemistry / Q000378:metabolism; D004926:Escherichia coli / Q000201:enzymology*; D029968:Escherichia coli Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D005971:Glutamates; D006868:Hydrolysis; D008969:Molecular Sequence Data; D010453:Peptide Synthases / Q000235:genetics; D010455:Peptides / Q000737:chemistry / Q000378:metabolism*; D010457:Peptidoglycan / Q000737:chemistry / Q000378:metabolism*; D016415:Sequence Alignment
chemical_list: D029968:Escherichia coli Proteins; D005971:Glutamates; D010455:Peptides; D010457:Peptidoglycan; D003960:Diaminopimelic Acid; D010450:Endopeptidases; D000581:Amidohydrolases; C019665:amidase; D010453:Peptide Synthases; C049145:UDP-N-acetylmuramoylalanyl-D-glutamate-2,6-diaminopimelate ligase