<p>Transaldolase (<db_xref db="EC" dbkey="2.2.1.2"/>) catalyses the reversible transfer of a three-carbon ketol unit from sedoheptulose 7-phosphate to glyceraldehyde 3-phosphate to form erythrose 4-phosphate and fructose 6-phosphate. This enzyme, together with transketolase, provides a link between the glycolytic and pentose-phosphate pathways. Transaldolase is an enzyme of about 34 kDa whose sequence has been well conserved throughout evolution. A lysine has been implicated [<cite idref="PUB00005649"/>] in the catalytic mechanism of the enzyme; it acts as a nucleophilic group that attacks the carbonyl group of fructose-6-phosphate.</p>