The cDNA of the gene pds from tomato, encoding the carotenoid biosynthesis enzyme phytoene desaturase, was cloned, and its nucleotide sequence was determined. Cells of Escherichia coli that expressed the tomato pds gene could convert phytoene to ξ-carotene. This result suggests that one polypeptide, the product of the pds gene, can carry out phytoene desaturation in the carotenoid biosynthetic pathway. Transcripts of the pds gene accumulate in orange tomato fruit, indicating transcriptional control of pds expression during fruit ripening. The deduced amino acid sequence of phytoene desaturase indicates that this enzyme in tomato contains 583 amino acids that are highly conserved with respect to the homologous enzymes in cyanobacteria and algae. The deduced amino acid sequences of the phytoene desaturases from other microorganisms (purple bacteria and fungi) appear to be evolutionary unrelated to those from green photosynthetic organisms.
|Number of pages||5|
|Journal||Proceedings of the National Academy of Sciences of the United States of America|
|State||Published - 1992|
- Carotenoid biosynthesis
- Phytoene desaturase