Isolation and sequence analysis of mutations inCEN5 DNA of yeast

We used a positive selection scheme involving a minichromosome maintenance mutantmcm2 to isolate mutations in centromeric DNA of the yeastSaccharomyces cerevisiae. Two mutations inCEN5 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 inCEN5 function.