1. Ben May Department for Cancer Research, The University of Chicago, Chicago, IL 60637, USA.
2. State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, China.
3. Peking–Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China.
4. Department of Biochemistry, Molecular Biology and Biophysics, The University of Minnesota at Twin Cities, Minneapolis, MN 55455, USA.
5. Synthetic and Functional Biomolecules Center; Beijing National Laboratory for Molecular Sciences; Key Laboratory of Bioorganic Chemistry and Molecular Engineering of the Ministry of Education; College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.