1. Department
of Chemistry, ∥Roy J. Carver Department of Biochemistry, Biophysics, and Molecular
Biology, and #Department
of Genetics, Development, and Cell Biology, Iowa State University, Ames, Iowa 50011, United States
2. Ames
Laboratory, U.S. Department of Energy, Ames, Iowa 50011, United States
3. Shanghai Jiao Tong University, School of Agriculture
and Biology, Shanghai, China