Department of Computational and Systems Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15260, USA, Department of Pharmacology, School of Medicine, Tsinghua University, Beijing 100084, China and Department of Structural Biology, Weizmann Institute of Science, Rehovot 76100, Israel Department of Computational and Systems Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15260, USA, Department of Pharmacology, School of Medicine, Tsinghua University, Beijing 100084, China and Department of Structural Biology, Weizmann Institute of Science, Rehovot 76100, Israel.|Department of Computational and Systems Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15260, USA, Department of Pharmacology, School of Medicine, Tsinghua University, Beijing 100084, China and Department of Structural Biology, Weizmann Institute of Science, Rehovot 76100, Israel.|Department of Computational and Systems Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15260, USA, Department of Pharmacology, School of Medicine, Tsinghua University, Beijing 100084, China and Department of Structural Biology, Weizmann Institute of Science, Rehovot 76100, Israel.|Department of Computational and Systems Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15260, USA, Department of Pharmacology, School of Medicine, Tsinghua University, Beijing 100084, China and Department of Structural Biology, Weizmann Institute of Science, Rehovot 76100, Israel.|Department of Computational and Systems Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15260, USA, Department of Pharmacology, School of Medicine, Tsinghua University, Beijing 100084, China and Department of Structural Biology, Weizmann Institute of Science, Rehovot 76100, Israel.