RAG-heptamer interaction in the synaptic complex is a crucial biochemical checkpoint for the 12/23 recombination rule.
In V(D)J recombination, the RAG1 and RAG2 protein complex cleaves the recombination signal sequences (RSSs), generating a hairpin structure at the coding end. The cleavage occurs only between two RSSs with different spacer lengths of 12 and 23 bp. Here we report that in the synaptic complex, recombination-activating gene (RAG) proteins interact with the 7-mer and unstack the adjacent base in the coding region. We generated a RAG1 mutant that exhibits reduced RAG-7-mer interaction, unstacking of the coding base, and hairpin formation. Mutation of the 23-RSS at the first position of the 7-mer, which has been reported to impair the cleavage of the partner 12-RSS, demonstrated phenotypes similar to those of the RAG1 mutant; the RAG interaction and base unstacking in the partner 12-RSS are reduced. We propose that the RAG-7-mer interaction is a critical step for coding DNA distortion and hairpin formation in the context of the 12/23 rule.
Nishihara
Tadashi
T
Department of Biophysics and Biochemistry, Graduate School of Science, The University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan.
Nagawa
Fumikiyo
F
Imai
Takeshi
T
Sakano
Hitoshi
H
D002460:Cell Line; D023902:Chromosome Pairing / Q000502:physiology*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D015321:Gene Rearrangement / Q000502:physiology*; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D008957:Models, Genetic; D009154:Mutation; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D011995:Recombination, Genetic / Q000502:physiology*
D004268:DNA-Binding Proteins; D018398:Homeodomain Proteins; D009687:Nuclear Proteins; C499311:RAG2 protein, human; C064658:RAG-1 protein