Oxidoreductases;
Acting on the CH-CH group of donors;
With unknown physiological acceptors
BRITE hierarchy

carotenoid beta-ring:acceptor oxidoreductase/methyltranferase (phi-ring forming)

carotenoid beta-end group + 2 acceptor = carotenoid phi-end group + 2 reduced acceptor [RN:R12115]

R12115 > R07541 R07857 R07858;
(other) R07560
Reaction

carotenoid beta-end group [CPD:C21915];
acceptor [CPD:C00028]

The enzyme, found in green sulfur bacteria, some cyanobacteria and some actinobacteria, introduces additional double bonds to the carotenoid beta-end group, leading to aromatization of the ionone ring. As a result, one of the methyl groups at C-1 is transferred to position C-2. It is involved in the biosynthesis of carotenoids with phi-type aromatic end groups such as chlorobactene, beta-isorenieratene, and isorenieratene.

EC 1.3.99.39 created 2018

1  [PMID:4774401]

Moshier SE, Chapman DJ

Biosynthetic studies on aromatic carotenoids. Biosynthesis of chlorobactene.

Biochem J 136:395-404 (1973)
DOI:10.1042/bj1360395

2  [PMID:10395965]

Krugel H, Krubasik P, Weber K, Saluz HP, Sandmann G.

Functional analysis of genes from Streptomyces griseus involved in the synthesis of isorenieratene, a carotenoid with aromatic end groups, revealed a novel type of carotenoid desaturase.

Biochim Biophys Acta 1439:57-64 (1999)
DOI:10.1016/S1388-1981(99)00075-X

3  [PMID:15292122]

Frigaard NU, Maresca JA, Yunker CE, Jones AD, Bryant DA.

Genetic manipulation of carotenoid biosynthesis in the green sulfur bacterium Chlorobium tepidum.

J Bacteriol 186:5210-20 (2004)
DOI:10.1128/JB.186.16.5210-5220.2004

[cte:CT0323]