About the Authors
Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona, United States of America
New England Biolabs Inc., Ipswich, Massachusetts, United States of America
Stanford Synchrotron Radiation Laboratory, Stanford University, Menlo Park, California, United States of America
The authors have declared that no competing interests exist.
The author(s) have made the following declarations about their contributions: Conceived and designed the experiments: CKP AA JB NH. Performed the experiments: CKP HKJ AA MIG NH. Analyzed the data: CKP MIG PWD NH. Contributed reagents/materials/analysis tools: CKP AA EJL JB NH. Wrote the paper: CKP JB NH.