Protein binding sites on centromere DNA in the dimorphic yeast Yarrowia lipolytica

Abstract

In the budding yeasts, centromere (CEN) DNA is confined within a short region of chromosome called point centromere. Yarrowia lipolytica forms budding-type yeast cells as well as mycelial cells depending on their growth conditions, thus imposing the interest on CEN architecture among distantly related budding yeasts. A canonical centromere-determining element (CDE) III site had been identified in Y. lipolytica CENs. Interestingly, CEN1 region contained two closely associated CDEIII sites, separated by 338 bp. To extend the similarity with canonical CENs in budding yeasts, we searched CDEI site(s) in CEN1 for their capacity to be bound by the purified Y. lipolytica transcription factor, Cbf1 protein. We found one or more possible Cbf1-binding sites at the outward region of one CDEIII site in CEN1. The strongest binding-site of Cbf1, a potential CDEI site, is involved in approximately 400 bp including the nearest CDEIII site. These results showed that the CDEI-CDEII-CDEIII architecture in budding yeast CEN is conserved in Y. lipolytica CEN1, but that the CDEII is longer with possible multiplication of CDEI sites.