Related Experiment Video
Updated: Jun 27, 2026
11:40
Preparation of the Mgm101 Recombination Protein by MBP-based Tagging Strategy
Published on: June 25, 2013
RecR-mediated modulation of RecF dimer specificity for single- and double-stranded DNA
Nodar Makharashvili1, Tian Mi, Olga Koroleva
1Edward A. Doisy Department of Biochemistry and Molecular Biology, St. Louis University School of Medicine, St. Louis, Missouri 63104, USA.
The Journal of Biological Chemistry
|November 20, 2008
Summary
The RecF protein
Area of Science:
- Molecular Biology
- Biochemistry
- Genetics
Background:
- RecF pathway proteins are crucial for DNA repair and replication restart in prokaryotes.
- RecF, RecR, and RecO initiate homologous recombination by loading RecA onto single-stranded DNA.
- The precise role of RecF in targeting DNA repair sites remains unclear.
Purpose of the Study:
- To investigate the DNA-binding properties and ATPase activity of Deinococcus radiodurans RecF.
- To elucidate the interaction between RecF and RecR and their combined effect on DNA binding.
- To determine if RecF recognizes single-stranded/double-stranded DNA junctions.
Main Methods:
- Biochemical assays to study RecF's ATP-dependent dimerization and DNA binding.
- Investigating the interaction stoichiometry and effects of RecR on RecF.
- Analyzing RecF and RecR binding to various DNA substrates, including ss/dsDNA junctions.
Main Results:
- RecF binds DNA as an ATP-dependent dimer, with activity influenced by DNA structure and RecR.
- RecR forms a tetramer with the RecF dimer, enhancing dsDNA affinity but destabilizing ssDNA binding and dimerization.
- RecF, alone or with RecR, does not preferentially bind to ss/dsDNA junctions.
Conclusions:
- RecF's DNA binding and ATPase activity are regulated by ATP, DNA structure, and RecR.
- RecR modulates RecF's DNA interaction through protein-protein interactions, not direct DNA binding.
- The RecFOR complex's specificity for damaged DNA boundaries arises from complex interactions, not solely ss/dsDNA junction recognition by RecF.
Related Concept Videos
02:53Conservative Site-specific Recombination and Phase Variation
Because the DNA segments are cut and reorganized in a direction-specific manner, site-specific recombination has emerged as an efficient genetic engineering technique. Flippase and Cyclization recombinases or Flp and Cre, respectively, are two members of the tyrosine recombinase family derived from bacteriophages, that are used to mediate site-specific DNA insertions, deletions, and targeted expression of proteins in mammalian cell lines.
The recognition sites for Cre recombinase called LoxP...
The recognition sites for Cre recombinase called LoxP...
02:31Homologous Recombination
The basic reaction of homologous recombination (HR) involves two chromatids that contain DNA sequences sharing a significant stretch of identity. One of these sequences uses a strand from another as a template to synthesize DNA in an enzyme-catalyzed reaction. The final product is a novel amalgamation of the two substrates. To ensure an accurate recombination of sequences, HR is restricted to the S and G2 phases of the cell cycle. At these stages, the DNA has been replicated already and the...
02:13Cooperative Binding of Transcription Regulators
Transcriptional regulators bind to specific cis-regulatory sequences in the DNA to regulate gene transcription. These cis-regulatory sequences are very short, usually less than ten nucleotide pairs in length. The short length means that there is a high probability of the exact same sequence randomly occurring throughout the genome. Since regulators can also bind to groups of similar sequences, this further increases the chances of random binding. Transcriptional regulators form dimers that...
01:11Restriction Enzymes
Restriction enzymes are bacterial enzymes used to cut DNA in a sequence-specific manner. To cleave DNA, they bind to specific palindromic sequences called restriction sites. Such palindromic DNA sequences or inverted repeats are commonly found in regions of functional significance, such as the origin of replication, gene operator sites, and regions containing transcription termination signals.
The host bacteria protect their own genomic DNA from these enzymes by methylating these sites. Some...
The host bacteria protect their own genomic DNA from these enzymes by methylating these sites. Some...
01:03Single-Strand DNA Binding Proteins
For successful DNA replication, the unwinding of double-stranded DNA must be accompanied by stabilization and protection of the separated single strands of the DNA. This crucial task is performed by single-strand DNA-binding (SSB) proteins. They bind to the DNA in a sequence-independent manner, which means that the nitrogenous bases of the DNA need not be present in a specific order for binding of SSB proteins to it. The binding of SSB proteins straightens single-stranded DNA (ssDNA) and makes...