Lyases;
Carbon-oxygen lyases;
Other carbon-oxygen lyases
BRITE hierarchy

4,5-unsaturated pyranuronate lyase (ring-opening)

(1) 4-deoxy-L-erythro-hex-4-enopyranuronate = (4S,5S)-4,5-dihydroxy-2,6-dioxohexanoate [RN:R13196];
(2) 4-deoxy-L-threo-hex-4-enopyranuronate = (4S,5R)-4,5-dihydroxy-2,6-dioxohexanoate [RN:R13197]

R13196 R13197
Reaction

4-deoxy-L-erythro-hex-4-enopyranuronate [CPD:C22713];
4-deoxy-L-threo-hex-4-enopyranuronate [CPD:C22712]

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.

EC 4.2.99.25 created 2023