About the Authors

Alex Engel

alex.engel@berkeley.edu

Current address: Department of Molecular and Cell Biology, University of California, Berkeley, California, United States of America

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

Pablo S. Aguilar

Current address: Institut Pasteur de Montevideo, Montevideo, Uruguay

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

Peter Walter

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

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

Conceived and designed the experiments: ACE PSA PW. Performed the experiments: ACE PSA. Analyzed the data: ACE PSA PW. Wrote the paper: ACE PW.