Affiliation: | aDivision of Biology, California Institute of Technology, Pasadena, CA, 91125;;bLaboratory of Molecular Immunology, The Rockefeller University, New York City, NY, 10065;;cCharite Universitätsmedizin, 10117 Berlin, Germany;;dHoward Hughes Medical Institute; and;eDepartment of Structural Biology, Weizmann Institute of Science, Rehovot 76100, Israel |