4.2.1.19 Biosynthesis of secondary metabolites - 01110 - 4.2.1.19 Histidine metabolism - 00340 - 4.2.1.19 histidine metabolism histidine metabolism - - 4.2.1.19 L-histidine biosynthesis - - HISTSYN-PWY 4.2.1.19 Metabolic pathways - 01100 -