InterPro domain: IPR033248

The C-terminal domain of transketolase has been proposed as a regulatory molecule binding site [ 1 , 2 ].

Transketolase 2.2.1.1 (TK) catalyzes the reversible transfer of atwo-carbon ketol unit from xylulose 5-phosphate to an aldose receptor, such asribose 5-phosphate, to form sedoheptulose 7-phosphate and glyceraldehyde 3-phosphate. This enzyme, together with transaldolase, provides a link betweenthe glycolytic and pentose-phosphate pathways.TK requires thiamine pyrophosphate as a cofactor. In most sources where TK hasbeen purified, it is a homodimer of approximately 70kDa subunits. TK sequencesfrom a variety of eukaryotic and prokaryotic sources [ 3 , 4 ] show that theenzyme has been evolutionarily conserved.In the peroxisomes of methylotrophic yeast Pichia angusta (Yeast) (Hansenula polymorpha), there is ahighly related enzyme, dihydroxy-acetone synthase (DHAS) 2.2.1.3 (alsoknown as formaldehyde transketolase), which exhibits a very unusualspecificity by including formaldehyde amongst its substrates.

1. Refined structure of transketolase from Saccharomyces cerevisiae at 2.0 A resolution. J. Mol. Biol. 238, 387-404
2. Three-dimensional structure of transketolase, a thiamine diphosphate dependent enzyme, at 2.5 A resolution. EMBO J. 11, 2373-9
3. Nucleotide and predicted amino acid sequence of a cDNA clone encoding part of human transketolase. Biochem. Biophys. Res. Commun. 183, 1159-66
4. DNA sequence of the yeast transketolase gene. Biochemistry 31, 1892-6