1 Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA.
2 Department of Life and Physical Sciences, Fisk University, Nashville, TN, 37232, USA; Center for Structural Biology, Vanderbilt University, Nashville, TN, 37232, USA.
3 Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA. Electronic address: antentor.o.hinton.jr@vanderbilt.edu.