DNA mismatches and GC-rich motifs target transposition by the RAG1/RAG2 transposase

AUTOR(ES)

Tsai, Chia-Lun

FONTE

Oxford University Press

RESUMO

In addition to their essential role in V(D)J recombination, the RAG proteins function as a transposase capable of inserting the V(D)J recombination intermediate, the signal end DNA fragment, into target DNA. RAG-mediated transposition has been suggested to contribute to genome instability and the development of lymphoid malignancies. Previous studies suggested that the RAG transposase exhibits a target site preference for GC rich sequences and hairpin structures. Here we demonstrate that a transposition hot spot (5′-GCCGCCGGGCC-3′), smaller portions of this hot spot and other GC rich motifs are able to target RAG-mediated transposition. Tracks of GC base pairs have been shown to have an unusually high rate of base pair breathing. Intriguingly, we find that DNA mismatches can efficiently target RAG-mediated transposition and suppress the use of other target sites. Hairpins, however, are not generally preferred targets. Our results indicate that target DNA melting may be a crucial step during RAG-mediated transposition, and that target site selection by the RAG transposase may be intimately linked to mutagenic and metabolic processes that transiently present favorable DNA structures to the transposition machinery.

Documentos Relacionados

• DNA helix: the importance of being GC-rich
• Betaine improves the PCR amplification of GC-rich DNA sequences.
• Improved mutation detection in GC-rich DNA fragments by combined DGGE and CDGE.
• PCR amplification of highly GC-rich DNA template after denaturation by NaOH.
• Detection of mutations in GC-rich DNA by bisulphite denaturing gradient gel electrophoresis.