A HIGHLY CONSERVED INTRASPECIES HOMOLOG OF THE SACCHAROMYCES-CEREVISIAE ELONGATION FACTOR-3 ENCODED BY THE HEF3 GENE

A paralog (intraspecies homolog) of the Saccharomyces cerevisiae YEF3 gene, encoding elongation factor-3, has been sequenced in the course o f the yeast genome project, and identified by database searching; this gene has been designated HEF3. Bioinformatic and Northern blot analys is indicate that the HEF3 gene is not expressed during vegetative grow th. Deletion of the HEF3 gene reveals no growth defects, nor any defec ts in mating or sporulation. A high copy 2 mu clone of HEF3 was constr ucted, and was shown to be unable to complement a null allele of yef3. Finally, an in vitro assay for ribosome-stimulated ATPase activity wa s performed with isogenic HEF3 and Delta hef3 strains; no difference i n biochemical activity could be detected in these strains. From these results, we conclude that the HEF3 gene does not encode a functional h omolog of YEF3. (C) 1998 John Wiley & Sons, Ltd.