PUBLICATION
DNA melting initiates the RAG catalytic pathway
- Authors
- Ru, H., Mi, W., Zhang, P., Alt, F.W., Schatz, D.G., Liao, M., Wu, H.
- ID
- ZDB-PUB-180801-7
- Date
- 2018
- Source
- Nature structural & molecular biology 25(8): 732-742 (Journal)
- Registered Authors
- Keywords
- none
- MeSH Terms
-
- Animals
- Catalysis
- DNA/metabolism*
- Humans
- Nucleic Acid Denaturation
- PubMed
- 30061602 Full text @ Nat. Struct. Mol. Biol.
Citation
Ru, H., Mi, W., Zhang, P., Alt, F.W., Schatz, D.G., Liao, M., Wu, H. (2018) DNA melting initiates the RAG catalytic pathway. Nature structural & molecular biology. 25(8):732-742.
Abstract
The mechanism for initiating DNA cleavage by DDE-family enzymes, including the RAG endonuclease, which initiates V(D)J recombination, is not well understood. Here we report six cryo-EM structures of zebrafish RAG in complex with one or two intact recombination signal sequences (RSSs), at up to 3.9-Å resolution. Unexpectedly, these structures reveal DNA melting at the heptamer of the RSSs, thus resulting in a corkscrew-like rotation of coding-flank DNA and the positioning of the scissile phosphate in the active site. Substrate binding is associated with dimer opening and a piston-like movement in RAG1, first outward to accommodate unmelted DNA and then inward to wedge melted DNA. These precleavage complexes show limited base-specific contacts of RAG at the conserved terminal CAC/GTG sequence of the heptamer, thus suggesting conservation based on a propensity to unwind. CA and TG overwhelmingly dominate terminal sequences in transposons and retrotransposons, thereby implicating a universal mechanism for DNA melting during the initiation of retroviral integration and DNA transposition.
Genes / Markers
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Orthology
Engineered Foreign Genes
Mapping