Yeast resolving enzyme CCE1 makes sequential cleavages in DNA junctions within the lifetime of the complex

Biochemistry. 2000 Apr 11;39(14):4082-9. doi: 10.1021/bi992785v.


CCE1 is a DNA junction-resolving enzyme of Saccharomyces cerevisiae. Such enzymes are required to make two symmetrically paired cleavages in order to resolve the four-way junction productively. Using a cruciform assay, we show here that CCE1 introduces two unilateral cleavages in a sequential manner. This requires that the protein remains bound to the junction, preventing branch migration of the point of strand exchange. From a detailed kinetic analysis, we find that the CCE1 cleavage at a given site is accelerated by a factor of 5-10 when it occurs subsequently to the initial cleavage. These properties ensure a productive resolution of the four-way junction and may be general for junction-resolving enzymes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • DNA, Fungal / chemistry
  • DNA, Fungal / genetics*
  • DNA, Fungal / metabolism
  • Endodeoxyribonucleases / chemistry
  • Endodeoxyribonucleases / genetics*
  • Endodeoxyribonucleases / metabolism
  • Holliday Junction Resolvases
  • Kinetics
  • Protein Binding
  • Recombination, Genetic*
  • Saccharomyces cerevisiae
  • Saccharomyces cerevisiae Proteins*


  • DNA, Fungal
  • Saccharomyces cerevisiae Proteins
  • Endodeoxyribonucleases
  • CCE1 protein, S cerevisiae
  • Holliday Junction Resolvases