The crtS gene of Xanthophyllomyces dendrorhous encodes a novel cytochrome-P450 hydroxylase involved in the conversion of β-carotene into astaxanthin and other xanthophylls

摘要: Abstract The conversion of β-carotene into xanthophylls is a subject great scientific and industrial interest. We cloned the crtS gene involved in astaxanthin biosynthesis from two producing strains Xanthophyllomyces dendrorhous: VKPM Y2410, an overproducing strain, wild type ATCC 24203. In both cases, ORF has length 3166 bp, including 17 introns, codes for protein 62.6 kDa with similarity to cytochrome-P450 hydroxylases. sequences 24203, 96594, 96815 show several nucleotide changes, but none them causes any amino acid substitution, except G2268 insertion 13th exon which change reading frame. A G1470 → A 5′ splicing region intron 8 was also found 96815. Both point mutations explain idiotrophy accumulation Mutants accumulating precursors biosynthetic pathway were selected parental strain Y2410 (red) showing different colors depending on compound accumulated. Two blocked astaxanthin, M6 (orange; 1% 71 times more β-carotene) M7 58 β-carotene, 135% canthaxanthin), whereas rest produced lower levels (5–66%) than strain. When expressed M7, canthaxanthin disappeared production partially restored. Moreover, restored when X. dendrorhous transformed gene. heterologously Mucor circinelloides conferring this fungus improved capacity synthesize β-cryptoxanthin zeaxanthin, hydroxylated compounds β-carotene. These results that xanthophylls, being potentially useful engineer carotenoid pathways.