View source for 1aa3

[[Image:1aa3.gif|left|200px]]<br /><applet load="1aa3" size="350" color="white" frame="true" align="right" spinBox="true" 
caption="1aa3" />
'''C-TERMINAL DOMAIN OF THE E. COLI RECA, NMR, MINIMIZED AVERAGE STRUCTURE'''<br />

==Overview==
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.

==About this Structure==
1AA3 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1AA3 OCA]. 

==Reference==
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, J Mol Biol. 1997 Nov 28;274(2):213-21. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=9398528 9398528]
[[Category: Escherichia coli]]
[[Category: Single protein]]
[[Category: Aihara, H.]]
[[Category: Ito, Y.]]
[[Category: Kurumizaka, H.]]
[[Category: RSGI, RIKEN Structural Genomics/Proteomics Initiative.]]
[[Category: Shibata, T.]]
[[Category: Terada, T.]]
[[Category: Yokoyama, S.]]
[[Category: double-stranded dna binding domain]]
[[Category: riken structural genomics/proteomics initiative]]
[[Category: rsgi]]
[[Category: structural genomics]]

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