Open AccessIdentification of MpaA, an Amidase in Escherichia coli That Hydrolyzes the γ- d -Glutamyl- meso- Diaminopimelate Bond in Murein Peptides
Author(s) -
Tsuyoshi Uehara,
James T. Park
Publication year - 2003
Publication title -
journal of bacteriology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.652
H-Index - 246
eISSN - 1067-8832
pISSN - 0021-9193
DOI - 10.1128/jb.185.2.679-682.2003
Subject(s) - biology , tripeptide , biochemistry , amidase , peptidoglycan , escherichia coli , diaminopimelic acid , peptide bond , endopeptidase , peptide sequence , amino acid , microbiology and biotechnology , enzyme , gene
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.