An interaction between a specified surface of the C-terminal domain of RecA protein and double-stranded DNA for homologous pairing.Aihara, H., Ito, Y., Kurumizaka, H., Terada, T., Yokoyama, S., Shibata, T.
(1997) J Mol Biol 274: 213-221
- PubMed: 9398528
- DOI: https://doi.org/10.1006/jmbi.1997.1403
- Primary Citation of Related Structures:
- PubMed Abstract:
RecA protein and its homologs catalyze homologous pairing of dsDNA and ssDNA, a critical reaction in homologous genetic recombination in various organisms from a virus, microbes to higher eukaryotes. In this reaction, RecA protein forms a nucleoprotein filament on ssDNA, which in turn binds to naked dsDNA for homology search. We suggested that the C-terminal domain of RecA protein plays a role in capturing the dsDNA. Here, we isolated the C-terminal domain as a soluble form and determined the solution structure by NMR spectroscopy. The overall folding of the NMR structure agrees with that of the corresponding part of the reported crystal structure, but a remarkable difference was found in a solvent-exposed region due to intermolecular contacts in the crystal. Then, we studied the interaction between the C-terminal domain and DNA, and found that significant chemical shift changes were induced in a specific region by titration with dsDNA. SsDNA induced a much smaller chemical shift perturbation. The difference of DNA concentrations to give the half-saturation of the chemical shift change showed a higher affinity of the C-terminal region toward dsDNA. Combined with our previous results, these provide direct evidence that the defined region in the C-terminal domain furnishes a binding surface for DNA.
The Institute of Physical and Chemical Research (RIKEN), Wako-shi, Japan.