1 Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education and School of Pharmaceutical Sciences, Wuhan University, 185 Donghu Road, Wuhan 430071, China; Hubei Engineering Laboratory for Synthetic Microbiology, Wuhan Institute of Biotechnology, 666 Gaoxin Road, Wuhan 430075, China. Electronic address: liutg@whu.edu.cn.
2 Department of Chemistry, The University of Texas at El Paso, El Paso, TX 79902, USA. Electronic address: ckim7@utep.edu.