1. Biology and Soft Matter Division; Oak Ridge National Laboratory; Oak Ridge TN 37831 USA
2. UT/ORNL Center for Molecular Biophysics; Biosciences Division; Oak Ridge National Laboratory; Oak Ridge TN 37831 USA
3. Solid State Physics Division; BARC; Trombay Mumbai 400085 India
4. Departments of Chemistry and Biology; Georgia State University; Atlanta GA 30302 USA
5. ISIS Facility; Rutherford Appleton Laboratory; Harwell Oxford Didcot OX11 0QX UK
6. Large-Scale Structures Group; Institut Laue Langevin; 71 avenue des Martyrs - CS 20156 38042 Grenoble Cedex 9 France
7. Laboratory of Chemical Physics; National Institute of Diabetes and Digestive and Kidney Diseases; National Institutes of Health, DHHS; Bethesda MD 20892-0520 USA