Interactions of the Escherichia coli primosomal PriB protein with the single-stranded DNA. Stoichiometries, intrinsic affinities, cooperativities, and base specificities.

ABSTRACT: Quantitative analysis of the interactions of the Escherichia coli primosomal PriB protein with a single-stranded DNA was done using quantitative fluorescence titration, photocrosslinking, and analytical ultracentrifugation techniques. Stoichiometry studies were done with a series of etheno-derivatives of single-stranded (ss) DNA oligomers. Interactions with the unmodified nucleic acids were studied, using the macromolecular competition titration (MCT) method. The total site-size of the PriB dimer-ssDNA complex, i.e. the maximum number of nucleotides occluded by the PriB dimer in the complex, is 12+/-1 nt. The protein has a single DNA-binding site, which is located centrally within the dimer and has a functionally homogeneous structure. The stoichiometry and photocrosslinking data show that

SUBMITTER: Szymanski MR 

PROVIDER: S-EPMC3226724 | biostudies-literature | 2010 Apr

REPOSITORIES: biostudies-literature