cd02012

Thiamine pyrophosphate (TPP) family, Transketolase (TK) subfamily, TPP-binding module; TK catalyzes the transfer of a two-carbon unit from ketose phosphates to aldose phosphates. In heterotrophic organisms, TK provides a link between glycolysis and the pentose phosphate pathway and provides precursors for nucleotide, aromatic amino acid and vitamin biosynthesis. In addition, the enzyme plays a central role in the Calvin cycle in plants. Typically, TKs are homodimers. They require TPP and divalent cations, such as magnesium ions, for activity.