Seminar

Constructing and reconstructing macromolecular complexes.

Dr. Santiago Ramón-Maiques

Constructing and reconstructing macromolecular complexes: Structural characterization of V(D)J recombinase and MuB helical filaments.

RAG1 and RAG2 proteins form the recombinase responsible for initiating V(D)J recombination, the specialized DNA rearrangement used by the immune system to assemble immunoglobulin and T-cell receptor genes. Our understanding of V(D)J recombination is hampered by the lack of structural information about RAG proteins and of their assembly into macromolecular complexes with the DNA. To better characterize this process, we developed a procedure to assemble and purify a stable RAG-DNA complex in amounts sufficient to characterize its composition, stoichiometry and molecular mass. We used transmission electron microscopy and image processing to reveal the general architecture of the complex, providing a framework for modeling RAG domains and their interactions.