Mutational and functional analysis of the beta-carotene ketolase involved in the production of canthaxanthin and astaxanthin.

ABSTRACT: Biosynthesis of the commercial carotenoids canthaxanthin and astaxanthin requires beta-carotene ketolase. The functional importance of the conserved amino acid residues of this enzyme from Paracoccus sp. strain N81106 (formerly classified as Agrobacterium aurantiacum) was analyzed by alanine-scanning mutagenesis. Mutations in the three highly conserved histidine motifs involved in iron coordination abolished its ability to catalyze the formation of ketocarotenoids. This supports the hypothesis that the CrtW ketolase belongs to the family of iron-dependent integral membrane proteins. Most of the mutations generated at other highly conserved residues resulted in partial activity. All partially active mutants showed a higher amount of adonixanthin accumulation than did the wild type when expr

SUBMITTER: Ye RW 

PROVIDER: S-EPMC1563626 | biostudies-literature | 2006 Sep

REPOSITORIES: biostudies-literature