Reaction: L-galactono-1,5-lactone + H2O = L-galactonate
Other name(s): lgaB (gene name); Bvu0220
Systematic name: L-glucono-1,5-lactone lactonohydrolase
Comments: The enzyme catalyses a step in the bacterial L-galactose utilization metabolic pathway. The upstream enzyme, EC 1.1.1.445 L-galactose 1-dehydrogenase (NADP+), produces L-galactono-1,5-lactone, which is spontaneously converted to L-galactono-1,4-lactone. However, the enzyme from Phocaeicola vulgatus hydrolyses L-galactono-1,5-lactone 300-fold faster than L-galactono-1,4-lactone. The product, L-galactonate, is further degraded by L-galactonate 5-dehydrogenase (EC 1.1.1.414).
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. Hobbs, M.E., Williams, H.J., Hillerich, B., Almo, S.C. and Raushel, F.M. L-Galactose metabolism in Bacteroides vulgatus from the human gut microbiota. Biochemistry 53 (2014) 4661-4670. [PMID: 24963813]