DNA concentration-dependent dissociation of EcoRI: direct transfer or reaction during hopping.

ABSTRACT: Direct transfer of proteins between DNA helices is a recognized important feature of the recognition site search process. Direct transfer is characterized by a dissociation rate that depends on total DNA concentration. This is taken as evidence for the formation of an intermediate DNA-protein-DNA ternary complex. We find that the dissociation rate of EcoRI-DNA-specific complexes at 80 mM NaCl depends on the concentration of competitor oligonucleotide suggesting that direct transfer contributes to EcoRI dissociation. This dependence on competitor DNA concentration is not seen at 180 mM salt. A careful examination of the salt concentration dependence of the dissociation rate, however, shows that the predictions for the formation of a ternary complex are not observed experimentally. The findi

SUBMITTER: Sidorova NY 

PROVIDER: S-EPMC3602783 | biostudies-literature | 2013 Mar

REPOSITORIES: biostudies-literature