1. Howard Hughes Medical Institute, University of California at San DiegoLa Jolla California92093
2. Department of PharmacologyUniversity of California at San DiegoLa Jolla California92093
3. University of Tennessee/Oak Ridge National Laboratory Center for Molecular Biophysics, Oak Ridge National LaboratoryOak Ridge Tennessee37831
4. Department of Biochemistry and Cellular and Molecular BiologyUniversity of TennesseeKnoxville Tennessee37996
5. Department of Chemistry and BiochemistryUniversity of California at San DiegoLa Jolla California92093