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cDNA for phytoene desaturase in Dunaliella salina and its expressed protein as indicators of phylogenetic position of the β‐carotene biosynthetic pathway
Author(s) -
Zhu YueHui,
Jiang JianGuo,
Chen XinWen
Publication year - 2007
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.2922
Subject(s) - biology , phytoene , complementary dna , dunaliella salina , phytoene desaturase , biochemistry , escherichia coli , dunaliella , biosynthesis , gene , algae , botany
The desaturations of phytoene are indispensable reaction phases to carotenogenesis. Full‐length cDNA for phytoene desaturase (PDS) in the chlorophyte Dunaliella salina was cloned by reverse transcriptase–polymerase chain reaction and rapid amplification of cDNA ends. The cDNA was expressed in Escherichia coli to produce an expected protein band of molecular mass 65 kDa, as well being expressed in another color complementary E. coli system in which the original phytoene desaturase coding gene crtI of the modified plasmid pACCAR16 ▵ IX was inactivated/complemented. But the colony of the E. coli system did not display the orange color which in the positive control colony appeared to be due to the accumulation of β‐carotene. It is deduced that the expressed enzyme from the green algae could only partially functionally complement the deleted bacterium CrtI , which means another carotene desaturase (ζ‐carotene desaturase) is required for formation of lycopene in D. salina , and the β‐carotene biosynthesis pathway in this alga is similar with that in cyanobacteria and higher plants. The presence of the cloned cDNA and its expressed phytoene desaturase indicated the phylogenetic position of the β‐carotene biosynthesis pathway of D. salina in the molecular evolution of carotenoid biosynthesis from bacteria to plants. Copyright © 2007 Society of Chemical Industry