1. Laboratory of Biomolecular NMR, St. Petersburg State University, St. Petersburg 199034, Russia
2. School of Life Sciences, Tsinghua University, Beijing 100084, China
3. Beijing Advanced Innovation Center for Structural Biology, Tsinghua University, Beijing 100084, China
4. Department of Chemistry & Chemical Biology, Rutgers University, Piscataway, New Jersey 08854, United States
5. Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, United States