Yanli Liu1, Li Li2, Jinrong Min3. 1. College of Life Sciences, Central China Normal University, Wuhan, China. 2. Structural Genomics Consortium and the Department of Physiology, University of Toronto, Toronto, Ontario, Canada. 3. College of Life Sciences, Central China Normal University, Wuhan, China, and at the Structural Genomics Consortium and the Department of Physiology, University of Toronto, Toronto, Ontario, Canada.