1. National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Chaoyang District, Beijing 100101, People's Republic of China
2. Department of Molecular and Developmental Genetics, Institute of Biology, Leiden University, Leiden, the Netherlands
3. Department of Chemical and Biomolecular Engineering and Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, Australia