Cobalt-precorrin 5A hydrolase explained

Cobalt-precorrin 5A hydrolase
Ec Number:	3.7.1.12

Cobalt-precorrin 5A hydrolase, CbiG (gene)) is an enzyme with systematic name cobalt-precorrin 5A acylhydrolase.^[1] This enzyme catalyses the following chemical reaction

cobalt-precorrin-5A + H₂O

\rightleftharpoons cobalt-precorrin-5B + acetaldehyde + 2 H⁺

This enzyme hydrolyses the ring A acetate delta-lactone of cobalt-precorrin-5A and releases a two-carbon fragment from the macrocyclic corrin ring as acetaldehyde. This is part of the biosynthetic pathway to cobalamin (vitamin B₁₂) in anaerobic bacteria such as Salmonella typhimurium and Bacillus megaterium.

See also

• Cobalamin biosynthesis

Notes and References

1. Kajiwara Y, Santander PJ, Roessner CA, Pérez LM, Scott AI . Genetically engineered synthesis and structural characterization of cobalt-precorrin 5A and -5B, two new intermediates on the anaerobic pathway to vitamin B12: definition of the roles of the CbiF and CbiG enzymes . Journal of the American Chemical Society . 128 . 30 . 9971–8 . August 2006 . 16866557 . 10.1021/ja062940a .