About the Authors

Shu-ou Shan

To whom correspondence should be addressed. E-mail: sshan@itsa.ucsf.edu

Affiliations Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, California, United States of America, Howard Hughes Medical Institute, University of California, San Francisco, California, United States of America

Robert M Stroud

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

Peter Walter

Affiliations Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, California, United States of America, Howard Hughes Medical Institute, University of California, San Francisco, California, United States of America

Competing Interests

The authors have declared that no conflicts of interest exist.

Author Contributions

SS and PW conceived and designed the experiments. SS performed the experiments. SS analyzed the data. SS contributed reagents/materials/analysis tools. SS, RMS, and PW wrote the paper.