ISOLATION AND CHARACTERIZATION OF A CDNA-ENCODING ARABIDOPSIS-THALIANA MEVALONATE KINASE BY GENETIC COMPLEMENTATION IN YEAST

A 1.64-kb cDNA encoding an Arabidopsis thaliana mevalonate kinase (MK) was cloned by complementation of the erg12-1 mutation affecting MK in the yeast Saccharomyces cerevisiae, and the nucleotide sequence was d etermined. The longest open reading frame encodes a protein of 378 ami no acids (aa) with a predicted molecular mass of 40 650 Da. A striking feature of the cDNA sequence is a long 5' untranslated region (322 bp ). The deduced aa sequence reveals that the plant enzyme shows strong similarities to the yeast and mammalian enzymes, especially the strong hydrophobicity percentage and several conserved regions. Southern ana lysis suggests that probably only one locus exists in the A. thaliana genome.