1.1.1.203 | crystal structures of an apo-form, a ternary form in complex with NADH and product, and an inactive Y136A mutant in complex with NAD+. Enzyme is a homohexamer. The monomer contains a Rossmann fold, essential for nucleotide binding. The ternary complex structure reveals a product, D-galactaro-1,5-lactone, which is bound above the nicotinamide ring. This product rearranges in solution to D-galactaro-1,4-lactone |