Salt-dependence of homology searching step by RecA nucleoprotein filaments
Journal
Journal of the Chinese Chemical Society
Journal Volume
60
Journal Issue
7
Pages
695-698
Date Issued
2013
Author(s)
Abstract
Abstract RecA recombinase binds onto single‐stranded DNA (ssDNA) and searches for its homologous sequence along double‐stranded DNA (dsDNA). This homologous recombination process is required for repairing double‐stranded DNA breaks. Here, we applied lateral magnetic tweezers to stretch duplex DNA molecules (Lambda DNA, 48,502 bp) in order to monitor the homology searching step by RecA nucleoprotein filaments at the single‐molecule level. From individual searching events, the diffusion coefficient of the RecA nucleoprotein filament is determined to be ∼ 0.5‐1 μm 2 /s. The nearly salt‐independence of the diffusion coefficients of RecA nucleoprotein filaments implies that our observed RecA searching events were mainly carried out by the one‐dimensional sliding mode.
Type
journal article