scholarly journals The Mycoplasma pneumoniae MPN229 gene encodes a protein that selectively binds single-stranded DNA and stimulates Recombinase A-mediated DNA strand exchange

2008 ◽  
Vol 8 (1) ◽  
pp. 167 ◽  
Author(s):  
Marcel Sluijter ◽  
Theo Hoogenboezem ◽  
Nico G Hartwig ◽  
Cornelis Vink
Keyword(s):  
Mycoplasma Pneumoniae ◽  
Strand Exchange ◽  
Single Stranded Dna ◽  
Dna Strand Exchange ◽  
Dna Strand

scholarly journals Fission Yeast Rad51 and Dmc1, Two Efficient DNA Recombinases Forming Helical Nucleoprotein Filaments

2005 ◽  
Vol 25 (11) ◽  
pp. 4377-4387 ◽  
Author(s):  
Synthia Sauvageau ◽  
Alicja Z. Stasiak ◽  
Isabelle Banville ◽  
Mickaël Ploquin ◽  
Andrzej Stasiak ◽  
...  
Keyword(s):  
Reca Protein ◽  
Strand Break ◽  
Strand Exchange ◽  
Exchange Reactions ◽  
Single Stranded Dna ◽  
Strand Breaks ◽  
Lower Eukaryotes ◽  
Dna Double Strand Break ◽  
Dna Strand Exchange ◽  
Dna Strand

ABSTRACT Homologous recombination is important for the repair of double-strand breaks during meiosis. Eukaryotic cells require two homologs of Escherichia coli RecA protein, Rad51 and Dmc1, for meiotic recombination. To date, it is not clear, at the biochemical level, why two homologs of RecA are necessary during meiosis. To gain insight into this, we purified Schizosaccharomyces pombe Rad51 and Dmc1 to homogeneity. Purified Rad51 and Dmc1 form homo-oligomers, bind single-stranded DNA preferentially, and exhibit DNA-stimulated ATPase activity. Both Rad51 and Dmc1 promote the renaturation of complementary single-stranded DNA. Importantly, Rad51 and Dmc1 proteins catalyze ATP-dependent strand exchange reactions with homologous duplex DNA. Electron microscopy reveals that both S. pombe Rad51 and Dmc1 form nucleoprotein filaments. Rad51 formed helical nucleoprotein filaments on single-stranded DNA, whereas Dmc1 was found in two forms, as helical filaments and also as stacked rings. These results demonstrate that Rad51 and Dmc1 are both efficient recombinases in lower eukaryotes and reveal closer functional and structural similarities between the meiotic recombinase Dmc1 and Rad51. The DNA strand exchange activity of both Rad51 and Dmc1 is most likely critical for proper meiotic DNA double-strand break repair in lower eukaryotes.

High-affinity and undissociated capillary electrophoresis for DNA strand exchange analysis

2020 ◽  
Vol 56 (54) ◽  
pp. 7403-7406
Author(s):  
Fangzhi Yu ◽  
Zheng Yuan ◽  
Dapeng Zhang ◽  
Yan Liu ◽  
Qiang Zhao ◽  
...  
Keyword(s):  
Capillary Electrophoresis ◽  
Strand Exchange ◽  
Exchange Reactions ◽  
Single Stranded Dna ◽  
High Affinity ◽  
Dna Strand Exchange ◽  
Dna Strand

Undissociated binding of SSB to single-stranded DNA facilitates fast gel-free capillary electrophoresis analysis of fundamentally important DNA strand exchange reactions.

scholarly journals Single-Molecule Insights into ATP-Dependent Conformational Dynamics of Nucleoprotein Filaments of Deinococcus radiodurans RecA

2020 ◽  
Vol 21 (19) ◽  
pp. 7389
Author(s):  
Aleksandr Alekseev ◽  
Galina Cherevatenko ◽  
Maksim Serdakov ◽  
Georgii Pobegalov ◽  
Alexander Yakimov ◽  
...  
Keyword(s):  
Dna Repair ◽  
Single Molecule ◽  
Deinococcus Radiodurans ◽  
Atp Hydrolysis ◽  
Conformational Dynamics ◽  
Strand Exchange ◽  
Single Stranded Dna ◽  
Dna Strand Exchange ◽  
High Conservation ◽  
Dna Strand

Deinococcus radiodurans (Dr) has one of the most robust DNA repair systems, which is capable of withstanding extreme doses of ionizing radiation and other sources of DNA damage. DrRecA, a central enzyme of recombinational DNA repair, is essential for extreme radioresistance. In the presence of ATP, DrRecA forms nucleoprotein filaments on DNA, similar to other bacterial RecA and eukaryotic DNA strand exchange proteins. However, DrRecA catalyzes DNA strand exchange in a unique reverse pathway. Here, we study the dynamics of DrRecA filaments formed on individual molecules of duplex and single-stranded DNA, and we follow conformational transitions triggered by ATP hydrolysis. Our results reveal that ATP hydrolysis promotes rapid DrRecA dissociation from duplex DNA, whereas on single-stranded DNA, DrRecA filaments interconvert between stretched and compressed conformations, which is a behavior shared by E. coli RecA and human Rad51. This indicates a high conservation of conformational switching in nucleoprotein filaments and suggests that additional factors might contribute to an inverse pathway of DrRecA strand exchange.

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