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Identification of a Gene Required for cis-to-trans Carotene Isomerization in Carotenogenesis of the Cyanobacterium Synechocystis sp. PCC 6803

2001; Oxford University Press; Volume: 42; Issue: 12 Linguagem: Inglês

10.1093/pcp/pce167

1471-9053

Kazumori Masamoto, Hajime Wada, Takakazu Kaneko, Shinichi Takaichi,

Antioxidant Activity and Oxidative Stress

A disruptive mutant of the sll0033 gene of the cyanobacterium Synechocystis sp. PCC 6803 produced primarily cis carotenes and small amounts of all-trans carotenes, but no xanthophylls, under dark conditions. Under light conditions, however, it produced normal carotenoids, that were the same as those produced by wild-type cells grown under both light and dark conditions. When the mutant cells cultured under dark conditions were irradiated, cis-isomers of carotenes were converted to all-trans lycopene. These findings demonstrate that this gene, designated crtH, is involved in the isomerization of cis-carotenes to all-trans forms in dark conditions, and that cis-carotenes were also converted to all-trans forms under light conditions by photoisomerization.