1. School of Life Sciences, Anhui University, Hefei, Anhui 230601, China
2. State Key Laboratory of Microbial Metabolism and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
3. Information and Engineering College, Dalian University, Dalian 116622, Liaoning, China
4. Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
5. Department of Mathematics, University of Wisconsin-Madison, Madison, WI 53706, USA
6. Oak Ridge National Laboratory, Biosciences Division, Oak Ridge, TN 37830, USA