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SSB binds to the RecG and PriA helicases in vivo in the absence of DNA
Author(s) -
Yu Cong,
Tan Hui Yin,
Choi Meerim,
Stanenas Adam J.,
Byrd Alicia K.,
D. Raney Kevin,
Cohan Christopher S.,
Bianco Piero R.
Publication year - 2016
Publication title -
genes to cells
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.912
H-Index - 115
eISSN - 1365-2443
pISSN - 1356-9597
DOI - 10.1111/gtc.12334
Subject(s) - helicase , biology , dna , microbiology and biotechnology , dna binding protein , dna replication , biochemistry , gene , transcription factor , rna
The E. coli single‐stranded DNA ‐binding protein ( SSB ) binds to the fork DNA helicases RecG and PriA in vitro . Typically for binding to occur, 1.3 m ammonium sulfate must be present, bringing into question the validity of these results as these are nonphysiological conditions. To determine whether SSB can bind to these helicases, we examined binding in vivo . First, using fluorescence microscopy, we show that SSB localizes PriA and RecG to the vicinity of the inner membrane in the absence of DNA damage. Localization requires that SSB be in excess over the DNA helicases and the SSB C‐terminus and both PriA and RecG be present. Second, using the purification of tagged complexes, our results show that SSB binds to PriA and RecG in vivo , in the absence of DNA . We propose that this may be the ‘storage form’ of RecG and PriA. We further propose that when forks stall, RecG and PriA are targeted to the fork by SSB , which, by virtue of its high affinity for single‐stranded DNA , allows these helicases to outcompete other proteins. This ensures their actions in the early stages of the rescue of stalled replication forks.