CLONING OF AN ARABIDOPSIS-THALIANA CDNA CODING FOR FARNESYL DIPHOSPHATE SYNTHASE BY FUNCTIONAL COMPLEMENTATION IN YEAST

A cDNA encoding farnesyl diphosphate synthase, an enzyme that synthesi zes C15 isoprenoid diphosphate from isopentenyl diphosphate and dimeth ylallyl diphosphate, was cloned from an Arabidopsis thaliana cDNA libr ary by complementation of a mutant of Saccharomyces cerevisiae deficie nt in this enzyme. The A. thaliana cDNA was also able to complement th e lethal phenotype of the erg20 deletion yeast mutant. As deduced from the full-length 1.22 kb cDNA nucleotide sequence, the polypeptide con tains 343 amino acids and has a relative molecular mass of 39 689. The predicted amino acid sequence presents about 50% identity with the ye ast, rat and human FPP synthases. Southern blot analyses, indicate tha t A. thaliana probably contains a single gene for farnesyl diphosphate synthase.