1. Department of Biochemistry, The University of Hong Kong, Pokfulam, Hong Kong, China.
2. Department of Physics, The University of Hong Kong, Pokfulam, Hong Kong, China.
3. Department of Chemistry, The University of Hong Kong, Pokfulam, Hong Kong, China.
4. Department of Physics, Hong Kong Baptist University, Kowloon Tong, Kowloon, Hong Kong, China.
5. Department of Physics and Center for Synthetic Microbiology, University of Marburg, 35032 Marburg, Germany.
6. Center for Theoretical Biological Physics, University of California at San Diego, La Jolla, CA 92093–0374, USA.