Center for Structural Biology, Vanderbilt University, Nashville, TN, United States of America.|Electrical Engineering and Computer Science, Vanderbilt University, Nashville, TN, United States of America.|Vanderbilt Vaccine Center, Vanderbilt University Medical Center, Nashville, TN, United States of America.|Center for Structural Biology, Vanderbilt University, Nashville, TN, United States of America.|Electrical Engineering and Computer Science, Vanderbilt University, Nashville, TN, United States of America.