1. Department of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, United States
2. Department of Chemistry, California State University Fresno, Fresno, California 93740, United States
3. Department of Molecular Biology, The Scripps Research Institute, La Jolla, California 92037, United States
4. Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, 115, Taiwan
5. Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana 59717, United States