1. Shanghai Center for Bioinformation and Technology, 100 Qinzhou Road, Shanghai 200235, P. R. China
2. Department of Chemistry, Tongji University, Shanghai 200092, P. R. China
3. Bioinformatics Center, Key Lab of Systems Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Graduate School of the Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031, P. R. China
4. College of Life Science and Biotechnology, Tongji University, Shanghai 200092, P. R. China