THE MUTATOR MUT7-1 OF SACCHAROMYCES-CEREVISIAE

The mut7-1 mutant of Saccharomyces cerevisiae is a cell-division-cycle mutant, exhibiting temperature-sensitive lethality and enhancement of mutator activity with increases in temperature. The base-sequence alt erations in mutants arising in a mut7-1 background differed from the c ontrol by there being a higher transversion/transition ratio and by th e much increased production of multi-base deletions. The deletions wer e, in every instance, associated with repeated oligonucleotide sequenc es (3-8 bases in length), where one of the two sequences was removed d uring the deletion process. The mutant mut7-1 failed to complement wit h cdc2, the temperature-sensitive mutant of the locus which encodes DN A polymerase III (delta).