D-erythro-1-(imidazol-4-yl)glycerol 3-phosphate = 3-(imidazol-4-yl)-2-oxopropyl phosphate + H2O H2O + L-histidinol phosphate = L-histidinol + phosphate Amino-acid biosynthesis; L-histidine biosynthesis; L-histidine from 5-phospho-alpha-D-ribose 1-diphosphate: step 6/9. Amino-acid biosynthesis; L-histidine biosynthesis; L-histidine from 5-phospho-alpha-D-ribose 1-diphosphate: step 8/9. In the N-terminal section; belongs to the histidinol-phosphatase family. In the C-terminal section; belongs to the imidazoleglycerol-phosphate dehydratase family.