ISOLATION AND SEQUENCE-ANALYSIS OF MUTATIONS IN CEN5 DNA OF YEAST

We used a positive selection scheme involving a minichromosome mainten ance mutant mcm2 to isolate mutations in centromeric DNA of the yeast Saccharomyces cerevisiae. Two mutations in CEN5 DNA were isolated. One of these mutations is a change from C:G to T:A at the 14th base pair of the CDEIII box, while the second is a complete deletion of all the CDE elements of this centromere. This work underscores the importance of the 14th base pair of CDEIII in CEN5 function.