1. UT/ORNL Center
for Molecular Biophysics, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6309, United States
2. Department
of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee 37996, United States
3. National
Bioenergy Center and Bioenergy Science Center, National Renewable Energy Laboratory, Golden, Colorado 80401, United States