1. Center for Protein Science and Crystallography; School of Life Sciences; The Chinese University of Hong Kong; Hong Kong; China
2. Department of Biochemistry; The University of Hong Kong; Hong Kong; China
3. Department of Physiology; The University of Hong Kong; Hong Kong; China
4. Department of Microbiology; The Chinese University of Hong Kong; Hong Kong; China
5. Department of Microbiology and Environmental Toxicology; University of California Santa Cruz; Santa Cruz; CA; USA