Yeast TKL1 gene encodes a transketolase that is required for efficient glycolysis and biosynthesis of aromatic amino acid

A gene encoding transketolase, TKL1, was cloned from the budding yeast Saccharomyces cerevisiae using oligonucleotide primers derived from protein sequence data. The TKL1 sequence predicts a 74-kDa polypeptide which is related to other transkeletolases. A can be subdivided into three evolutionary branches. We also found that the transketolases are related to another vitamin B sub(1)-dependent enzyme: the E1 subunit of pyruvate dehydrogenase from Escherichia coli). We found that growth on fermentable carbon sources, but not on gluconeogenic carbon sources, is reduced in cells disrupted for TKL1.