Department of Biochemistry, Stanford University School of Medicine, Stanford, CA 94305, USA, Department of Physics, Stanford University, Stanford, CA 94305, USA.|Department of Biochemistry, Stanford University School of Medicine, Stanford, CA 94305, USA, Department of Physics, Stanford University, Stanford, CA 94305, USA.|Department of Biochemistry, Stanford University School of Medicine, Stanford, CA 94305, USA, Department of Physics, Stanford University, Stanford, CA 94305, USA.|Department of Biochemistry, Stanford University School of Medicine, Stanford, CA 94305, USA, Department of Physics, Stanford University, Stanford, CA 94305, USA.|Department of Biochemistry, Stanford University School of Medicine, Stanford, CA 94305, USA, Department of Physics, Stanford University, Stanford, CA 94305, USA.|Department of Biochemistry, Stanford University School of Medicine, Stanford, CA 94305, USA, Department of Physics, Stanford University, Stanford, CA 94305, USA.