TY - JOUR
T1 - SSB functions as a sliding platform that migrates on DNA via reptation
AU - Zhou, Ruobo
AU - Kozlov, Alexander G.
AU - Roy, Rahul
AU - Zhang, Jichuan
AU - Korolev, Sergey
AU - Lohman, Timothy M.
AU - Ha, Taekjip
N1 - Funding Information:
We thank all the members of Ha laboratory for experimental help and discussion. These studies were supported by grants from the National Institutes of Health (GM030498 to T.M.L., GM073837 to S.K., and RR025341 and GM065367 to T.H.) and the National Science Foundation (0822613 and 0646550 to T.H.). T.H. is an employee of the Howard Hughes Medical Institute.
PY - 2011/7/22
Y1 - 2011/7/22
N2 - SSB proteins bind to and control the accessibility of single-stranded DNA (ssDNA), likely facilitated by their ability to diffuse on ssDNA. Using a hybrid single-molecule method combining fluorescence and force, we probed how proteins with large binding site sizes can migrate rapidly on DNA and how protein-protein interactions and tension may modulate the motion. We observed force-induced progressive unraveling of ssDNA from the SSB surface between 1 and 6 pN, followed by SSB dissociation at ∼10 pN, and obtained experimental evidence of a reptation mechanism for protein movement along DNA wherein a protein slides via DNA bulge formation and propagation. SSB diffusion persists even when bound with RecO and at forces under which the fully wrapped state is perturbed, suggesting that even in crowded cellular conditions SSB can act as a sliding platform to recruit and carry its interacting proteins for use in DNA replication, recombination and repair.
AB - SSB proteins bind to and control the accessibility of single-stranded DNA (ssDNA), likely facilitated by their ability to diffuse on ssDNA. Using a hybrid single-molecule method combining fluorescence and force, we probed how proteins with large binding site sizes can migrate rapidly on DNA and how protein-protein interactions and tension may modulate the motion. We observed force-induced progressive unraveling of ssDNA from the SSB surface between 1 and 6 pN, followed by SSB dissociation at ∼10 pN, and obtained experimental evidence of a reptation mechanism for protein movement along DNA wherein a protein slides via DNA bulge formation and propagation. SSB diffusion persists even when bound with RecO and at forces under which the fully wrapped state is perturbed, suggesting that even in crowded cellular conditions SSB can act as a sliding platform to recruit and carry its interacting proteins for use in DNA replication, recombination and repair.
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U2 - 10.1016/j.cell.2011.06.036
DO - 10.1016/j.cell.2011.06.036
M3 - Article
C2 - 21784244
AN - SCOPUS:79960804204
SN - 0092-8674
VL - 146
SP - 222
EP - 232
JO - Cell
JF - Cell
IS - 2
ER -