Related Experiment Video
Updated: May 2, 2026
11:42
Iterative Optimization of DNA Duplexes for Crystallization of SeqA-DNA Complexes
Published on: November 1, 2012
9.3K
Bacillus subtilis SsbA and dATP regulate RecA nucleation onto single-stranded DNA.
Begoña Carrasco1, Candela Manfredi, Silvia Ayora
1Department of Microbial Biotechnology, Centro Nacional de Biotecnología, CSIC, C/Darwin 3, Campus Universidad Autónoma de Madrid, 28049 Madrid, Spain.
DNA Repair
|May 13, 2008
Summary
Bacillus subtilis RecA protein shows higher efficiency in DNA strand exchange using deoxyadenosine triphosphate (dATP) compared to adenosine triphosphate (ATP). The study reveals how SsbA protein modulates RecA activity, impacting DNA repair mechanisms.
Area of Science:
- Molecular Biology
- Biochemistry
- Genetics
Background:
- RecA protein is crucial for DNA repair and recombination.
- The role of nucleotide cofactors (ATP vs. dATP) in RecA function is not fully understood.
- Single-stranded DNA binding proteins (SsbA) are known to interact with RecA.
Purpose of the Study:
- To investigate the differential hydrolysis of dATP versus ATP by Bacillus subtilis RecA.
- To elucidate the regulatory effects of SsbA on RecA's ATPase and DNA strand exchange activities.
- To compare the efficiency of DNA strand exchange mediated by RecA in the presence of dATP versus ATP.
Main Methods:
- Enzymatic assays measuring ATPase activity of RecA.
- DNA strand exchange assays under varying conditions.
- Investigating the impact of SsbA addition order on RecA activity.
Main Results:
- Bacillus subtilis RecA preferentially hydrolyzes dATP over ATP.
- SsbA significantly modulates RecA's dATPase activity and DNA strand exchange efficiency.
- DNA strand exchange is more efficient with dATP, requiring less RecA compared to ATP.
Conclusions:
- dATP binding and hydrolysis, along with SsbA, act as regulatory mechanisms for the RecA nucleoprotein filament.
- These findings provide insights into the dynamic regulation of RecA's function in DNA metabolism.
- The differential nucleotide preference and SsbA modulation highlight the complexity of RecA-mediated processes.
More Related Videos
Related Concept Videos
03:01The Replisome
31.2K
DNA replication is carried out by a large complex of proteins that act in a coordinated matter to achieve high-fidelity DNA replication. Together this complex is known as the DNA replication machinery or the replisome.
The synthesis of the leading and lagging strands is a highly coordinated process. To explain this, the “Trombone model” was proposed by Bruce Alberts in 1980. The DNA loop formation starts when a primer is synthesized on the parent lagging strand. The loop grows with...
The synthesis of the leading and lagging strands is a highly coordinated process. To explain this, the “Trombone model” was proposed by Bruce Alberts in 1980. The DNA loop formation starts when a primer is synthesized on the parent lagging strand. The loop grows with...
31.2K
02:10Translesion DNA Polymerases
9.3K
Translesion (TLS) polymerases rescue stalled DNA polymerases at sites of damaged bases by replacing the replicative polymerase and installing a nucleotide across the damaged site. Doing so, TLS allows additional time for the cell to repair the damage before resuming regular DNA replication.
TLS polymerases are found in all three domains of life - archaea, bacteria, and eukaryotes. Of the different classes of TLS polymerases, members of the Y family are fitted with specialized structures that...
TLS polymerases are found in all three domains of life - archaea, bacteria, and eukaryotes. Of the different classes of TLS polymerases, members of the Y family are fitted with specialized structures that...
9.3K
02:31Homologous Recombination
58.8K
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...
58.8K
02:37Restarting Stalled Replication Forks
5.1K
DNA replication is initiated at sites containing predefined DNA sequences known as origins of replication. DNA is unwound at these sites by the minichromosome maintenance (MCM) helicase and other factors such as Cdc45 and the associated GINS complex.The unwound single strands are protected by replication protein A (RPA) until DNA polymerase starts synthesizing DNA at the 5’ end of the strand in the same direction as the replication fork. To prevent the replication fork from falling apart,...
5.1K
00:43Bacterial RNA Polymerase
19.9K
Unlike eukaryotes, bacteria use a single RNA Polymerase (RNAP) to transcribe all genes. The different subunits of bacterial RNAPhave distinct functions. The multisubunit structure of the bacterial RNAP helps the enzyme to maintain catalytic function, facilitate assembly, interact with DNA and RNA, and self-regulate its activity.
In most genes, the transcription site is a single base present upstream of the coding sequence. Though RNAP is a catalytically efficient enzyme, it does not recognize...
In most genes, the transcription site is a single base present upstream of the coding sequence. Though RNAP is a catalytically efficient enzyme, it does not recognize...
19.9K
01:03Single-Strand DNA Binding Proteins
12.9K
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...
12.9K