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A stable RAG1-RAG2-DNA complex that is active in V(D)J cleavage
1Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-0540, USA.
Cell
|January 10, 1997
Summary
The RAG1 and RAG2 proteins form a stable complex at DNA recombination sites, initiating V(D)J recombination. This complex
Area of Science:
- Molecular Biology
- Immunology
- Genetics
Background:
- V(D)J recombination is crucial for adaptive immunity.
- RAG1 and RAG2 proteins initiate this process by cleaving DNA at specific sites.
Purpose of the Study:
- To investigate the initial interaction between RAG1/RAG2 proteins and recombination signal sequences.
- To characterize the structure and function of the protein-DNA complex formed during V(D)J recombination.
Main Methods:
- Protein-DNA binding assays to demonstrate specific interaction.
- Biochemical assays to analyze cleavage activity and complex stability.
- Divalent cation dependency studies.
Main Results:
- RAG1 and RAG2 specifically bind to recombination signal sequences, forming a stable complex.
- The complex requires conserved heptamer and nonamer motifs and both RAG proteins.
- The complex can nick or hairpin the DNA, with activity dependent on divalent cations (Ca2+, Mg2+, Mn2+).
- Complex destabilizes and dissociates after DNA cleavage.
Conclusions:
- A stable cleavage complex is formed by RAG1/RAG2 at V(D)J recombination sites.
- This complex is a key intermediate in the V(D)J recombination pathway.
- Divalent cations play a critical role in regulating the cleavage activity of the RAG complex.
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