thiamine diphosphate biosynthesis KEGG:map00730 GO:0009229 UPa:UPA00060 Biosynthesis of thiamin pyrophosphate (THI-PP, TPP), the active form of thiamine cofactor (vitamin B1). It has essential functions, for example in carbohydrate and branched-chain amino-acid metabolism. All organisms able to to produce THI-PP initially assemble THI-P by coupling 4-amino-2-methyl-5-diphosphomethylpyrimidine and 4-methyl-5-(2-phosphoethyl)-thiazole. THI-P is then converted to TPP. The two heterocyclic precursors of thiamine pyrophosphate are synthesized through independant pathways. WARNING: the DXP_MHETP_BIOS sub-pathway is temporary. It will be refined as soon as knowledge will be available. thiamine-PP (THI-PP)(TPP) biosynthesis KEGG:map01100 pathway thiamin diphosphate biosynthesis cofactor biosynthesis thiamine metabolism