About the Authors
Center for Theoretical Biological Physics and Department of Physics, Rice University, Houston, Texas, United States of America
The authors have declared that no competing interests exist.
Conceived and designed the experiments: HL JKN JNO. Performed the experiments: HL JKN. Analyzed the data: HL. Wrote the paper: HL JKN JNO. Wrote the software: JKN HL.