Open AccessA single polypeptide catalyzing the conversion of phytoene to zeta-carotene is transcriptionally regulated during tomato fruit ripening.
Author(s) -
Iris Pecker,
Daniel Chamovitz,
Hartmut Linden,
Gerhard Sandmann,
Joseph Hirschberg
Publication year - 1992
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.89.11.4962
Subject(s) - phytoene , phytoene desaturase , biochemistry , biology , phytoene synthase , carotenoid , complementary dna , gene , escherichia coli , amino acid , carotene , peptide sequence , biosynthesis , botany
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 zeta-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 evolutionarily unrelated to those from green photosynthetic organisms.