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.
Publication types
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Amidohydrolases* / chemistry
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Amidohydrolases* / genetics
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Amidohydrolases* / metabolism
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Amino Acid Sequence
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Bacillus / enzymology
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Diaminopimelic Acid / chemistry
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Diaminopimelic Acid / metabolism*
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Endopeptidases / chemistry
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Endopeptidases / metabolism
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Escherichia coli / enzymology*
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Escherichia coli Proteins* / chemistry
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Escherichia coli Proteins* / genetics
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Escherichia coli Proteins* / metabolism
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Glutamates
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Hydrolysis
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Molecular Sequence Data
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Peptide Synthases / genetics
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Peptides / chemistry
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Peptides / metabolism*
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Peptidoglycan / chemistry
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Peptidoglycan / metabolism*
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Sequence Alignment
Substances
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Escherichia coli Proteins
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Glutamates
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Peptides
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Peptidoglycan
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Diaminopimelic Acid
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Endopeptidases
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Amidohydrolases
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amidase
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Peptide Synthases
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UDP-N-acetylmuramoylalanyl-D-glutamate-2,6-diaminopimelate ligase