. "Catalysis of the reaction: 5-aminoimidazole ribonucleotide + S-adenosylmethionine = 4-amino-5-hydroxymethyl-2-methylpyrimidine phosphate + 5'deoxyadenosine." . . . "ThiC" . "4-amino-5-hydroxymethyl-2-methylpyrimidine phosphate synthase activity" . "HMP-P synthase activity" . . . .