[2017 Fall Life Sciences & IBB Seminar]

▶Subject: Crystal structure of the V(D)J recombinase RAG1-RAG2

▶Speaker: Prof. Min-Sung Kim (POSTECH)

▶Date: 4:30PM/Sep. 8 (Fri)/2017

▶Place: Auditorium(1F), Postech Biotech Center

▶Abctract
V(D)J recombination in the vertebrate immune system generates a highly diverse population of immunoglobulins and T-cell receptors by combinatorial joining of segments of coding DNA. The RAG1–RAG2 protein complex initiates this site-specific recombination by cutting DNA at specific sites flanking the coding segments. Here we report the crystal structure of the mouse RAG1–RAG2 complex at 3.2A˚ resolution. The 230-kilodalton RAG1–RAG2 heterotetramer is ‘Y-shaped’, with the amino-terminal domains of the two RAG1 chains forming an intertwined stalk. Each RAG1–RAG2 heterodimer composes one arm of the ‘Y’, with the active site in the middle andRAG2 at its tip. TheRAG1–RAG2 structure rationalizes more than 60 mutations identified in immunodeficient patients, as well as a large body of genetic and biochemical data. The architectural similarity between RAG1 and the hairpin-forming transposases Hermes and Tn5 suggests the evolutionary conservation of these DNA rearrangements.