Identification of the mpl gene encoding UDP-N-acetylmuramate: L-alanyl-gamma-D-glutamyl-meso-diaminopimelate ligase in Escherichia coli and its role in recycling of cell wall peptidoglycan.
A gene, mpl, encoding UDP-N-acetylmuramate:L-alanyl-gamma-D-glutamyl-meso-diaminopimelat e ligase was recognized by its amino acid sequence homology with murC as the open reading frame yjfG present at 96 min on the Escherichia coli map. The existence of such an enzymatic activity was predicted from studies indicating that reutilization of the intact tripeptide L-alanyl-gamma-D-glutamyl-meso-diaminopimelate occurred and accounted for well over 30% of new cell wall synthesis. Murein tripeptide ligase activity could be demonstrated in crude extracts, and greatly increased activity was produced when the gene was cloned and expressed under control of the trc promoter. A null mutant totally lacked activity but was viable, showing that the enzyme is not essential for growth.
Mengin-Lecreulx
D
D
Unité de Recherche Associée 1131 du Centre National de la Recherche Scientifique, Université Paris-Sud, Orsay, France. mengin@ebp.u-psud.fr
van Heijenoort
J
J
Park
J T
JT
D000119:Acetylmuramyl-Alanyl-Isoglutamine / Q000031:analogs & derivatives / Q000378:metabolism; D000595:Amino Acid Sequence; D002473:Cell Wall / Q000378:metabolism*; D002874:Chromosome Mapping; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics* / Q000254:growth & development; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D009154:Mutation; D010453:Peptide Synthases / Q000235:genetics*; D010457:Peptidoglycan / Q000378:metabolism*; D011994:Recombinant Proteins / Q000096:biosynthesis; D014538:Uridine Diphosphate N-Acetylmuramic Acid / Q000378:metabolism
D010457:Peptidoglycan; D011994:Recombinant Proteins; D014538:Uridine Diphosphate N-Acetylmuramic Acid; D000119:Acetylmuramyl-Alanyl-Isoglutamine; C035104:muramylNAc-Ala-isoGln-Lys-tripeptide; D010453:Peptide Synthases; C049145:UDP-N-acetylmuramoylalanyl-D-glutamate-2,6-diaminopimelate ligase