THE ESCHERICHIA-COLI MRAY GENE ENCODING UDP-N-ACETYLMURAMOYL-PENTAPEPTIDE - UNDECAPRENYL-PHOSPHATE PHOSPHO-N-ACETYLMURAMOYL-PENTAPEPTIDE TRANSFERASE

Amplification of the mraY gene, previously called open reading frame Y (ORF-Y, 1,080 bp), at 2 min in the chromosome map of Escherichia coli enhanced the activity of UDP-N-acetylmuramoyl-pentapeptide: Undecaprenyl-phosophate phospho-N-acetylmuramoyl-pentapeptide transferase (EC 2.7.8.13). This enzyme catalyzes the formation of undecaprenyl-pyophosphoryl-N-acetylmuramoyl-pentapeptide from UDP-N-acetylmuramoyl-pentapeptide and undecaprenyl-phosphate, the first step in the lipid cycle reactions in biosynthesis of bacterial cell wall peptidoglycans. The enhanced enzyme activity was sensitive to tunicamycin, and the amino acid sequence deduced from the base sequence of the mraY gene showed certain similarity with that of the tunicamycin-sensitive N-acetylglucosamine-1-phosphate transferase of Saccharomyces cerevisiae. Very probably mraY is the structural gene for the above enzyme.