CLONING AND CHARACTERIZATION OF THE KLDIM1 GENE FROM KLUYVEROMYCES-LACTIS ENCODING THE M(2)(6)A DIMETHYLASE OF THE 18S RIBOSOMAL-RNA

The KlDIM1 gene encoding the m(2)(6)A rRNA dimethylase was cloned from a Kluyveromyces lactis genomic library using a PCR amplicon from the Saccharomyces cerevisiae ScDIM1 gene as probe. The KlDIM1 gene encodes a 320-amino acid protein which shows 81% identity to ScDim1p from S. cerevisiae and 25% identity to ksgAp from Escherichia coli. Complement ation of the kasugamycin-resistant ksgA-mutant of E. coli lacking dime thylase activity demonstrates that KlDim1p is the functional homologue of the bacterial enzyme. Multiple alignment of dimethylases from prok aryotes and yeasts shows that the two yeast enzymes display distinctiv e structural motives including a putative nuclear localization signal. (C) 1997 by John Wiley & Sons, Ltd.