1 Key Laboratory of Ministry of Education for Protein Science, School of Life Sciences, Tsinghua University, Beijing, 100084, China.
2 Key Laboratory of Ministry of Education for Protein Science, School of Life Sciences, Tsinghua University, Beijing, 100084, China. zhixinwang@mail.tsinghua.edu.cn.
3 Key Laboratory of Ministry of Education for Protein Science, School of Life Sciences, Tsinghua University, Beijing, 100084, China. pan-xm@mail.tsinghua.edu.cn.