1AA3: C-TERMINAL DOMAIN OF THE E. COLI RECA, NMR, MINIMIZED AVERAGE STRUCTURE

Citation:
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.
PDB ID: 1AA3Download
MMDB ID: 55106
PDB Deposition Date: 1997/1/22
Updated in MMDB: 2007/11
Experimental Method:
solution nmr
Source Organism:
Similar Structures:
Biological Unit for 1AA3: monomeric; determined by author
Molecular Components in 1AA3
Label Count Molecule
Protein (1 molecule)
1
Reca(Gene symbol: recA)
Molecule annotation
* Click molecule labels to explore molecular sequence information.

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