Is transketolase-like protein, TKTL1, transketolase?

► Transketolase-like protein 1 (TKTL1) is a marker of certain tumor tissues. ► Site-specific mutagenesis was used for modifying human transketolase (hTKT) gene. ► The mutant (DhTKT) had a deletion of 38 amino acid residues in hTKT protein. ► This deletion is the major difference between hTKT and TKTL1. ► We demonstrate that DhTKT is devoid of transketolase activity and lacks bound ThDP.