Transaldolase B is an enzyme of the Class I aldose family and catalyzes the reversible transer of a dihydroxyacetone moiety, derived from fructose-6-phosphate, to erythrose-4-phosphate yielding sedohepptulose-7-phosphate. This reaction is a part of the pentose phosphate pathway, an anabolic pathway that utilizes the 6 carbons of glucose to generate 5 carbon sugars and reducing equivalents. A common feature of the members of this enzyme family is the formation of a covalent intermediate (Schiff base) between an active site lysine residue and the substrate during catalysis. The enzyme is of considerable interest as a catalyst in stereospecific organic synthesis. It is also a target for drug design, because Transaldolase (TAL) is involved in oxidative stress and apoptosis, in multiple sclerosis, and its deficiency leads to severe symptoms in human.