A distinctive single-stranded DNA-binding protein from the Archaeon Sulfolobus solfataricus

Cynthia A. Haseltine, Stephen C. Kowalczykowski

Research output: Contribution to journalArticle

46 Scopus citations

Abstract

Single-stranded DNA binding proteins (SSBs) have been identified in all three domains of life. Here, we report the identification of a novel crenarchaeal SSB protein that is distinctly different from its euryarchaeal counterparts. Rather than comprising four DNA-binding domains and a zinc-finger motif within a single polypeptide of 645 amino acids, as for Methanococcus jannaschii, the Sulfolobus solfataricus SSB protein (SsoSSB) has a single DNA-binding domain in a polypeptide of just 148 amino acids with a eubacterial-like acidic C-terminus. SsoSSB protein was purified to homogeneity and found to form tetramers in solution, suggesting a quaternary structure analogous to that of E. coli SSB protein, despite possessing DNA-binding domains more similar to those of eukaryotic Replication Protein A (RPA). We demonstrate distributive binding of SsoSSB to ssDNA at high temperature with an apparent site size of approximately five nucleotides (nt) per monomer. Additionally, the protein is functional both in vitro and in vivo, stimulating RecA protein-mediated DNA strand-exchange and rescuing the ssb-1 lethal mutation of E. coli respectively. We discuss possible evolutionary relationships amongst the various members of the SSB/RPA family.

Original languageEnglish (US)
Pages (from-to)1505-1515
Number of pages11
JournalMolecular Microbiology
Volume43
Issue number6
DOIs
StatePublished - 2002

ASJC Scopus subject areas

  • Molecular Biology
  • Microbiology

Fingerprint Dive into the research topics of 'A distinctive single-stranded DNA-binding protein from the Archaeon Sulfolobus solfataricus'. Together they form a unique fingerprint.

  • Cite this