Structure of the single-stranded-DNA-binding domain of replication protein A bound to DNA

Nature. 1997 Jan 9;385(6612):176-81. doi: 10.1038/385176a0.


The single-stranded-DNA-binding proteins (SSBs) are essential for DNA function in prokaryotic and eukaryotic cells, mitochondria, phages and viruses. The structures of four SSBs have been solved, but the molecular details of the interaction of SSBs with DNA remain speculative. We report here the crystal structure at 2.4 A resolution of the single-stranded-DNA-binding domain of human replication protein A (RPA) bound to DNA. Replication protein A is a heterotrimeric SSB that is highly conserved in eukaryotes. The largest subunit, RPA70, binds to single-stranded (ss)DNA and mediates interactions with many cellular and viral proteins. The DNA-binding domain, which lies in the middle of RPA70, comprises two structurally homologous subdomains oriented in tandem. The ssDNA lies in a channel that extends from one subdomain to the other. The structure of each RPA70 subdomain is similar to those of the bacteriophage SSBs, indicating that the mechanism of ssDNA-binding is conserved.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Cloning, Molecular
  • Crystallography, X-Ray
  • DNA / chemistry*
  • DNA / metabolism
  • DNA-Binding Proteins / chemistry*
  • DNA-Binding Proteins / metabolism
  • Escherichia coli
  • Humans
  • Models, Molecular
  • Molecular Sequence Data
  • Protein Binding
  • Protein Conformation*
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / metabolism
  • Replication Protein A


  • DNA-Binding Proteins
  • RPA1 protein, human
  • Recombinant Proteins
  • Replication Protein A
  • DNA

Associated data

  • PDB/1JMC