THE MURG GENE OF THE ESCHERICHIA-COLI CHROMOSOME ENCODING UDP-N-ACETYLGLUCOSAMINE - UNDECAPRENYL-PYROPHOSPHORYL-N-ACETYLMURAMOYL-PENTAPEPTIDE N-ACETYLGLUCOSAMINYL TRANSFERASE

The murG gene located in the m ra region at 2 min on the Escherichia coli chromosome map was found to be responsible for UDP-GlcNAc: undecaprenyl-pyrophosphoryl-N-acetylmuramoyl-pentapeptide N-acetylglucosaminyl transferase activity in lipid cycle reactions of cell wall peptidoglycan synthesis. murG was concluded to be the structural gene for this enzyme from the following findings: (1) Expression of GlcNAc-transferase activity by the murG gene seemed to be thermosensitive when the chromosome carried an amber mutation in murG and a thermosensitive sup mutation. (2) Overproduction of the murG product caused an increase of GlcNAc-transferase activity. Incidentally, chemically phosphorylated polyprenol was shown to function as a carrier in lipid cycle reactions in peptidoglycan synthesis in E. coli.