Welcome! Click here to login or here to register.
 |
|||||||||||||||||||
|
|||||||||||||||||||
 |
|||||||||||||||||||
"Molecular visualization of the yeast Dmc1 protein ring and Dmc1-ssDNA nucleoprotein complex." |
Chang YC, Lo YH, Lee MH, Leng CH, Hu SM, Chang CS, Wang TF |
Published April 26, 2005 in Biochemistry volume 44 .
Pubmed ID: 15835894
Abstract:
| Saccharomyces cerevisiae Dmc1, a meiosis-specific homologue of RecA, catalyzes homologous pairing and strand exchange during meiotic DNA recombination. The purified budding yeast Dmc1 (ScDmc1) protein exhibits much weaker recombinase activity in vitro as compared to that of the Escherichia coli RecA protein. Using atomic force microscopy (AFM) with carbon nanotube tips, we found ScDmc1 forms rings with an external diameter of 18 nm and a central cavity of 4 nm. In the presence of single-stranded DNA (ssDNA), the majority of the ScDmc1 protein (90%) bound DNA as protein rings; only a small faction (10%) was able to form filamentous structure. In contrast, nearly all RecA proteins form fine helical nucleoprotein filaments with ssDNA under identical conditions. RecA-mediated recombinase activity is initiated through the nucleation of RecA onto ssDNA to form helical nucleoprotein filaments. Our results support the notion that ScDmc1 becomes catalytically active only when it forms a helical nucleoprotein filament with ssDNA. |
This publication refers to following REPAIRtoire entries:
Last modification of this entry: Oct. 6, 2010
Add your own comment!
There is no comment yet.
|
|
|
|