ATP-mediated conformational changes in the RecA filament.
The crystal structure of the E. coli RecA protein was solved more than 10 years ago, but it has provided limited insight into the mechanism of homologous genetic recombination. Using electron microscopy, we have reconstructed five different states of RecA-DNA filaments. The C-terminal lobe of the RecA protein is modulated by the state of the distantly bound nucleotide, and this allosteric coupling can explain how mutations and truncations of this C-terminal lobe enhance RecA's activity. A model generated from these reconstructions shows that the nucleotide binding core is substantially rotated from its position in the RecA crystal filament, resulting in ATP binding between subunits. This simple rotation can explain the large cooperativity in ATP hydrolysis observed for RecA-DNA filaments.
VanLoock
Margaret S
MS
Department of Biochemistry and Molecular Genetics, University of Virginia Health Sciences, Charlottesville, VA 22908, USA.
Yu
Xiong
X
Yang
Shixin
S
Lai
Alex L
AL
Low
Claudia
C
Campbell
Michael J
MJ
Egelman
Edward H
EH
D000255:Adenosine Triphosphate / Q000378:metabolism*; D001665:Binding Sites; D004926:Escherichia coli / Q000737:chemistry / Q000378:metabolism; D008854:Microscopy, Electron; D008958:Models, Molecular; D011487:Protein Conformation; D011938:Rec A Recombinases / Q000737:chemistry* / Q000378:metabolism / Q000648:ultrastructure
D000255:Adenosine Triphosphate; D011938:Rec A Recombinases