1. Division of Biology and Howard Hughes Medical Institute, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125 (USA)
2. Division of Medical Genetics, Department of Pediatrics, Harbor‐UCLA Medical Center and Los Angeles Biomedical Research Institute, 1124 West Carson Street, Torrance, CA 90502 (USA)
3. University of Kansas Specialized Chemistry Center, 2034 Becker Drive, Structural Biology Center, West Campus, Lawrence, KS 66047 (USA)