THI4 — Neurospora crassa

Summary

NCU11173 (NcTHI4) on Neurospora crassa chromosome 3 encodes a thiamine-phosphate pyrophosphorylase with hydroxyethylthiazole kinase activity, possessing thiamine phosphate synthase and ribokinase-like domains. The enzyme catalyzes thiamin-phosphate diphosphorylase activity (EC 2.5.1.3) and hydroxyethylthiazole kinase activity (EC 2.7.1.50), binding magnesium and ATP. It is associated with thiamine diphosphate biosynthesis and thiamin anabolism, localizing to the cytoplasm and cytosol. The gene is linked to multiple phenotypes including inviability, haploinsufficiency, increased autophagy, increased heat sensitivity, decreased competitive fitness, decreased chemical resistance, abnormal chromosome maintenance, and altered protein and RNA accumulation. Studies of related genes in other species connect the family to oxidative stress response, acid pH resistance, desiccation resistance, nitrogen utilization, vegetative growth, and stress resistance.