1. Center
for Theoretical Biological Physics, Rice University, Houston, Texas 77030, United States
2. Department
of Physics and Astronomy, Rice University, Houston, Texas 77005, United States
3. Max Delbrück Center for Molecular Medicine, Berlin 13125, Germany
4. Fritz Haber Institute of the Max Planck Society, Berlin 14195, Germany
5. Verna
and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston 77030, Texas, United States
6. Department
of Bioengineering, Rice University, Houston, Texas 77005, United States
7. Departments
of Chemistry and Biosciences, Rice University, Houston, Texas 77005, United States