THE ESCHERICHIA-COLI RUVB BRANCH MIGRATION PROTEIN FORMS DOUBLE HEXAMERIC RINGS AROUND DNA.
P NATL ACAD SCI USA
7618 - 7622.
The RuvB protein is induced in Escherichia coil as part of the SOS response to DNA damage. It is required for genetic recombination and the postreplication repair of DNA. In vitro, the RuvB protein promotes the branch migration of Holliday junctions and has a DNA helicase activity in reactions that require ATP hydrolysis. We have used electron microscopy, image analysis, and three-dimensional reconstruction to show that the RuvB protein, in the presence of ATP, forms a dodecamer on double-stranded DNA in which two stacked hexameric rings encircle the DNA and are oriented in opposite directions with D-6 symmetry. Although helicases are ubiquitous and essential for many aspects of DNA repair, replication, and transcription, three-dimensional reconstruction of a helicase has not yet been reported, to our knowledge. The structural arrangement that is seen may be common to other helicases, such as the simian virus 40 large tumor antigen.
|Title:||THE ESCHERICHIA-COLI RUVB BRANCH MIGRATION PROTEIN FORMS DOUBLE HEXAMERIC RINGS AROUND DNA|
|Keywords:||DNA HELICASE, 3-DIMENSIONAL RECONSTRUCTION, ELECTRON MICROSCOPY, TERMINATION FACTOR-RHO, HOLLIDAY JUNCTIONS, HELICASE ACTIVITY, PHYSICAL-PROPERTIES, FUNCTIONAL INTERACTIONS, K-12 REVEALS, RECOMBINATION, REPAIR, RNA, RECONSTRUCTION|
|UCL classification:||UCL > School of Life and Medical Sciences > Faculty of Life Sciences > Biosciences (Division of) > Structural and Molecular Biology|
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