Figure 1. Schematic representation of proposed pathways and regulation mechanisms involved in UDP-N-acetylglucosamine synthesis by Lactobacillus casei. PTS, phosphoenol-pyruvate phosphotransferase system; GlcNAc, N-acetylglucosamine; Glk, glucokinase; Pgi, phosphoglucose isomerase; NagA, GlcNAc-6P deacetylase; NagB, glucosamine-6-phosphate deaminase; GlmS, glucosamine-6-phosphate synthase; GlmM, phosphoglucosamine mutase; GlmU, glucosamine-1-phosphate acetyltransferase/N-acetylglucosamine-1-phosphate uridyltransferase. Bold lines represent the regulatory features of the UDP-GlcNAc pathway.