Structural and phylogenetic analysis of a novel ζ-carotene desaturase from Dunaliella bardawil, a unicellular alga that accumulates large amounts of β-carotene

Abstract

Due to the high demand for carotenoids in the global market, more and more attention is being paid to the molecular elucidation of carotenogenesis in Dunaliella for the massive production of β-carotene. The complementary deoxyribonucleic acid (cDNA) of a novel carotenogenic enzyme, ζ-carotene desaturase (Zds), was isolated from Dunaliella bardawil using polymerase chain reaction. The full-length cDNA was 2209 base pairs (bp) long, containing an 1749-bp putative open reading frame that encoded a deduced protein sequence of 582 amino acids with an estimated molecular weight of 64.429 kDa. The D. bardawil Zds was a nonsecretory protein that may be located in the chloroplast. The D. bardawil Zds had a closer relationship with chlorophyte and higher plants Zdses than with those of other species in the phylogenetic analysis. The three-dimensional structure of the D. bardawil Zds is predicted. © 2011, by the American Society of Limnology and Oceanography, Inc.