UDP-N-acetylglucosamine pyrophosphorylase; Catalyzes the last two sequential reactions in the de novo biosynthetic pathway for UDP-N-acetylglucosamine (UDP-GlcNAc). The C- terminal domain catalyzes the transfer of acetyl group from acetyl coenzyme A to glucosamine-1-phosphate (GlcN-1-P) to produce N- acetylglucosamine-1-phosphate (GlcNAc-1-P), which is converted into UDP-GlcNAc by the transfer of uridine 5-monophosphate (from uridine 5- triphosphate), a reaction catalyzed by the N-terminal domain. In the C-terminal section; belongs to the transferase hexapeptide repeat family.

Amidophosphoribosyltransferase; Catalyzes the formation of phosphoribosylamine from phosphoribosylpyrophosphate (PRPP) and glutamine.

Ribose 5-phosphate isomerase B; Identified by match to protein family HMM PF02502; match to protein family HMM TIGR00689; match to protein family HMM TIGR01120.

Ribose-5-phosphate isomerase; Catalyzes the reversible conversion of ribose-5-phosphate to ribulose 5-phosphate.

Phosphomannomutase/phosphoglucomutase; Identified by similarity to SP:P26276.

Putative ribose-phosphate pyrophosphokinase; Identified by similarity to SP:P14193; match to protein family HMM PF00156; match to protein family HMM TIGR01251; Belongs to the ribose-phosphate pyrophosphokinase family.

Phosphoglucomutase; Identified by match to protein family HMM PF00408; match to protein family HMM PF02878; match to protein family HMM PF02879; match to protein family HMM PF02880; match to protein family HMM TIGR01132.

Hydrolase, NUDIX family; Identified by match to protein family HMM PF00293.

ATP phosphoribosyltransferase; Catalyzes the condensation of ATP and 5-phosphoribose 1- diphosphate to form N'-(5'-phosphoribosyl)-ATP (PR-ATP). Has a crucial role in the pathway because the rate of histidine biosynthesis seems to be controlled primarily by regulation of HisG enzymatic activity. Belongs to the ATP phosphoribosyltransferase family. Long subfamily.