Regulation of single-stranded DNA binding by the C termini of Escherichia coli single-stranded DNA-binding (SSB) protein.

ABSTRACT: The homotetrameric Escherichia coli single-stranded DNA-binding (SSB) protein plays a central role in DNA replication, repair, and recombination. In addition to its essential activity of binding to transiently formed single-stranded (ss) DNA, SSB also binds an array of partner proteins and recruits them to their sites of action using its four intrinsically disordered C-terminal tails. Here we show that the binding of ssDNA to SSB is inhibited by the SSB C-terminal tails, specifically by the last 8 highly acidic amino acids that comprise the binding site for its multiple partner proteins. We examined the energetics of ssDNA binding to short oligodeoxynucleotides and find that at moderate salt concentration, removal of the acidic C-terminal ends increases the intrinsic affinity for ssDNA and

SUBMITTER: Kozlov AG 

PROVIDER: S-EPMC2878057 | biostudies-literature | 2010 May

REPOSITORIES: biostudies-literature