TY - JOUR
T1 - Escherichia coli RecBC helicase has two translocase activities controlled by a single ATPase motor
AU - Wu, Colin G.
AU - Bradford, Christina
AU - Lohman, Timothy M.
N1 - Funding Information:
We thank R. Galletto, C. Fischer, A. Lucius, K. Maluf, E. Galburt, N. Baker, P. Burgers, G. Smith, T. Ellenberger, S. Kowalczykowski and E. Antony for valuable discussions and comments on the manuscript, G. Smith (Fred Hutchinson Cancer Research Center), A. Taylor (Fred Hutchinson Cancer Research Center) and D. Julin (University of Maryland, College Park) for plasmids and cell lines and T. Ho (Washington University School of Medicine) for synthesis and purification of DNA. This work was supported in part by US National Institutes of Health grant GM045948 (to T.M.L.).
PY - 2010/10
Y1 - 2010/10
N2 - E. coli RecBCD is a DNA helicase with two ATPase motors (RecB, a 3′→5′ translocase, and RecD, a 5′→3′ translocase) that function in repair of double-stranded DNA breaks. The RecBC heterodimer, with only the RecB motor, remains a processive helicase. Here we examined RecBC translocation along single-stranded DNA (ssDNA). Notably, we found RecBC to have two translocase activities: the primary translocase moves 3′→5′, whereas the secondary translocase moves RecBC along the opposite strand of a forked DNA at a similar rate. The secondary translocase is insensitive to the ssDNA backbone polarity, and we propose that it may fuel RecBCD translocation along double-stranded DNA ahead of the unwinding fork and ensure that the unwound single strands move through RecBCD at the same rate after interaction with a crossover hot-spot indicator (Chi) sequence.
AB - E. coli RecBCD is a DNA helicase with two ATPase motors (RecB, a 3′→5′ translocase, and RecD, a 5′→3′ translocase) that function in repair of double-stranded DNA breaks. The RecBC heterodimer, with only the RecB motor, remains a processive helicase. Here we examined RecBC translocation along single-stranded DNA (ssDNA). Notably, we found RecBC to have two translocase activities: the primary translocase moves 3′→5′, whereas the secondary translocase moves RecBC along the opposite strand of a forked DNA at a similar rate. The secondary translocase is insensitive to the ssDNA backbone polarity, and we propose that it may fuel RecBCD translocation along double-stranded DNA ahead of the unwinding fork and ensure that the unwound single strands move through RecBCD at the same rate after interaction with a crossover hot-spot indicator (Chi) sequence.
UR - https://www.scopus.com/pages/publications/77957785417
U2 - 10.1038/nsmb.1901
DO - 10.1038/nsmb.1901
M3 - Article
C2 - 20852646
AN - SCOPUS:77957785417
SN - 1545-9993
VL - 17
SP - 1210
EP - 1217
JO - Nature Structural and Molecular Biology
JF - Nature Structural and Molecular Biology
IS - 10
ER -