About the Authors

Jeffrey H Chuang

Affiliation Department of Biochemistry and Biophysics, University of California, San Francisco, California, United States of America

Hao Li

To whom correspondence should be addressed. E-mail: haoli@genome.ucsf.edu

Affiliation Department of Biochemistry and Biophysics, University of California, San Francisco, California, United States of America

Competing Interests

The authors have declared that no conflicts of interest exist.

Author Contributions

JC and HL conceived and designed the experiments. JC performed the experiments. JC and HL analyzed the data. JC contributed reagents/materials/analysis tools. JC wrote the paper.