Kluyveromyces marxianus small DNA fragments contain both autonomous replicative and centromeric elements that also function in Kluyveromyces lactis

Two fragments containing both an autonomous replicating sequence (ARS) and a centromere have been isolated and sequenced from the yeast Kluyveromyces marxianus . The ARS and centromeric core sequences are only 500 bp apart, but ARS activity could be separated from the centromeric sequences. Centromeric sequences are organized in a similar way to those of budding yeasts: two well‐conserved elements: CDEI (5′ TCACGTG 3′) and CDEIII (5′ TNTTCCGAAAGTWAAA 3′), are separated by a 165 bp AT‐rich (± 90%) CDEII element whose length is twice that of Saccharomyces cerevisiae CDEII but almost identical to that of K. lactis . The ARS‐core consensus sequence (5′ TTTATTGTT 3′) is also similar to that of K. lactis . Both ARS and centromeric elements function in this strain, albeit inefficiently, but not in S. cerevisiae . A third ARS‐containing fragment with a different organization has been isolated and sequenced. The nucleotide sequences of DNA fragments reported in this paper will appear in the EMB data library under the accession numbers: Z31562, Z31563, Z31564.