Genes specifying the thiamin monophos¬phate phosphatase and adenylated thiazole diphosphatase steps in fungal and plant thiamin biosynthesis remain unknown, as do genes for thia¬min diphosphate (ThDP) hydrolysis in thiamin metabolism. A distinctive Nudix domain fused to thia¬min di¬phos¬phokin¬ase (Tnr3) in Schizo¬sacc¬¬h¬aromyces pombe was evaluated as a candidate for these funct¬ions....