A novel SMC protein complex in Schizosaccharomyces pombe contains the Rad18 DNA repair protein

EMBO J. 2000 Apr 3;19(7):1691-702. doi: 10.1093/emboj/19.7.1691.

Abstract

In Schizosaccharomyces pombe, rad18 is an essential gene involved in the repair of DNA damage produced by ionizing radiation and in tolerance of UV-induced DNA damage. The Rad18 protein is a member of the SMC (structural maintenance of chromosomes) superfamily, and we show that, like the other SMC proteins in condensin and cohesin, Rad18 is a component of a high-molecular-weight complex. This complex contains at least six other proteins, the largest of which is Spr18, a novel SMC family member closely related to Rad18, and likely to be its heterodimeric partner. SMC proteins have ATP-binding domains at the N- and C-termini, and two extended coiled-coil domains separated by a hinge in the middle. We show that the N-terminal ATP-binding domain of Rad18 is essential for all functions, and overexpression of an N-terminal mutant has a dominant-negative effect. We have identified an important mutation (S1045A) near the C-terminus of Rad18 that separates its repair and essential roles. Potential models for the role of the Rad18-Spr18 complex during DNA repair are discussed.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Triphosphatases / chemistry
  • Adenosine Triphosphatases / genetics
  • Adenosine Triphosphatases / metabolism
  • Amino Acid Sequence
  • Cell Cycle Proteins*
  • Chromosomal Proteins, Non-Histone / chemistry*
  • Chromosomal Proteins, Non-Histone / genetics
  • Chromosomal Proteins, Non-Histone / metabolism*
  • DNA Repair
  • DNA-Binding Proteins / chemistry*
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism*
  • Fungal Proteins / chemistry*
  • Fungal Proteins / genetics
  • Fungal Proteins / metabolism*
  • Genes, Fungal
  • Genetic Complementation Test
  • Macromolecular Substances
  • Molecular Sequence Data
  • Molecular Weight
  • Mutagenesis, Site-Directed
  • Phenotype
  • Saccharomyces cerevisiae Proteins*
  • Schizosaccharomyces / genetics
  • Schizosaccharomyces / metabolism*
  • Schizosaccharomyces pombe Proteins*
  • Sequence Homology, Amino Acid

Substances

  • Cell Cycle Proteins
  • Chromosomal Proteins, Non-Histone
  • DNA-Binding Proteins
  • Fungal Proteins
  • Macromolecular Substances
  • RAD18 protein, S cerevisiae
  • Saccharomyces cerevisiae Proteins
  • Schizosaccharomyces pombe Proteins
  • Smc5 protein, S pombe
  • Adenosine Triphosphatases