1. Department of Biomedical Engineering, Southern University of Science and Technology, No 1088, Xueyuan Rd, Nanshan District, Shenzhen, Guangdong 518055, P. R. China
2. School of Chemistry and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, UK
3. School of Food Science and Nutrition and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, UK
4. Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai 200040, P. R. China