Abstract:
:We study dsDNA-RecA interactions by exerting forces in the pN range on single DNA molecules while the interstrand topological state is controlled owing to a magnetic tweezers setup. We show that unwinding a duplex DNA molecule induces RecA polymerization even at moderate force. Once initial polymerization has nucleated, the extent of RecA coverage still depends on the degree of supercoiling: exerting a positive or negative torsional constraint on the fiber forces partial depolymerization, with a strikingly greater stability when ATPgammaS is used as a cofactor instead of ATP. This nucleofilament's sensitivity to topology might be a way for the bacterial cell to limit consumption of precious RecA monomers when DNA damage is addressed through homologous recombination repair.
journal_name
Biophys Jjournal_title
Biophysical journalauthors
Fulconis R,Bancaud A,Allemand JF,Croquette V,Dutreix M,Viovy JLdoi
10.1529/biophysj.104.043059subject
Has Abstractpub_date
2004-10-01 00:00:00pages
2552-63issue
4eissn
0006-3495issn
1542-0086pii
S0006-3495(04)73726-1journal_volume
87pub_type
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