Reaction: (1) 4-deoxy-L-erythro-hex-4-enopyranuronate = (4S,5S)-4,5-dihydroxy-2,6-dioxohexanoate
(2) 4-deoxy-L-threo-hex-4-enopyranuronate = (4S,5R)-4,5-dihydroxy-2,6-dioxohexanoate
Glossary: 4-deoxy-L-erythro-hex-4-enopyranuronate = 4,5-unsaturated D-galacturonate
4-deoxy-L-threo-hex-4-enopyranuronate = 4,5-unsaturated D-mannuronate/L-guluronate
(4S,5S)-4,5-dihydroxy-2,6-dioxohexanoate = 5-keto-4-deoxyuronate
(4S,5R)-4,5-dihydroxy-2,6-dioxohexanoate = 5-dehydro-4-deoxy-D-glucuronate
Other name(s): kdgF (gene name)
Systematic name: 4,5-unsaturated pyranuronate lyase (ring-opening)
Comments: The enzyme, found in bacteria and archaea, is involved in the degradation of polysaccharides such as alginate and pectin. The enzyme catalyses a pyranose ring-opening reaction followed by enol-keto tautomerization.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. Hobbs, J.K., Lee, S.M., Robb, M., Hof, F., Barr, C., Abe, K.T., Hehemann, J.H., McLean, R., Abbott, D.W. and Boraston, A.B. KdgF, the missing link in the microbial metabolism of uronate sugars from pectin and alginate. Proc. Natl. Acad. Sci. USA 113 (2016) 6188-6193. [PMID: 27185956]