Department of Medical Biochemistry and Biophysics, Karolinska Institutet, SE-171xe2x80x8977 Stockholm, Sweden.|Department of Medical Biochemistry and Biophysics, Karolinska Institutet, SE-171xe2x80x8977 Stockholm, Sweden.|Department of Medical Biochemistry and Biophysics, Karolinska Institutet, SE-171xe2x80x8977 Stockholm, Sweden.|Department of Medical Biochemistry and Biophysics, Karolinska Institutet, SE-171xe2x80x8977 Stockholm, Sweden.|Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA 94305, USA.|Department of Medical Biochemistry and Biophysics, Karolinska Institutet, SE-171xe2x80x8977 Stockholm, Sweden.|Department of Medical Biochemistry and Biophysics, Karolinska Institutet, SE-171xe2x80x8977 Stockholm, Sweden.