Specific interaction between a Saccharomyces cerevisiae protein and a DNA element associated with certain autonomously replicating sequences

Proc Natl Acad Sci U S A. 1988 Feb;85(3):743-6. doi: 10.1073/pnas.85.3.743.


We have isolated a protein from Saccharomyces cerevisiae that binds specifically to a nucleotide sequence associated with the autonomously replicating sequence (ARS) ARS120, located in the telomeric region of a yeast chromosome. "Footprinting" analysis revealed that a 26-base-pair DNA sequence, 5'-CAAGTGCCGTGCATAATGATGTGGGT-3', was protected by this protein from DNase I digestion. A plasmid containing 48 direct tandem repeats of this oligonucleotide was constructed and used to affinity-purify the binding activity. The purified protein, OBF1 (origin binding factor), showed specific binding to ARS120. The 26-base-pair OBF1-protected sequence was sufficient for the recognition and binding of the protein, since the mobility of a DNA fragment containing the synthetic binding site was retarded in agarose gels when incubated with OBF1. By performing competition experiments with a number of different ARSs, we showed that OBF1 binds tightly to some but not all ARSs. Interestingly, OBF1 does not appear to have a discernible affinity for ARS1 or the ARSs associated with mating type loci, HML alpha and HMRa, which are substrates for a DNA-binding activity reported by others. Since OBF1 appears to bind to DNA associated with a number of ARSs, we suggest that this protein may have a function related to ARS activity, perhaps in the initiation of DNA replication at selected ARSs.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • DNA Replication
  • DNA, Fungal / metabolism*
  • DNA-Binding Proteins / isolation & purification
  • DNA-Binding Proteins / metabolism*
  • Fungal Proteins / isolation & purification
  • Fungal Proteins / metabolism*
  • Recombinant Proteins / metabolism
  • Regulatory Sequences, Nucleic Acid*
  • Replicon*
  • Saccharomyces cerevisiae / analysis*


  • DNA, Fungal
  • DNA-Binding Proteins
  • Fungal Proteins
  • Recombinant Proteins