Catalyzes the phosphorylation of thiamine to thiamine pyrophosphate. Can also catalyze the phosphorylation of pyrithiamine to pyrithiamine pyrophosphate. ATP + thiamine = AMP + H(+) + thiamine diphosphate Cofactor biosynthesis; thiamine diphosphate biosynthesis; thiamine diphosphate from thiamine: step 1/1. Homodimer. Detected in kidney and liver, and at lower levels in heart, brain and testis. May be due to intron retention. Belongs to the thiamine pyrophosphokinase family.