Department of Biochemistry & Cellular and Molecular Biology, The University of Tennessee, Knoxville, Tennessee, United States of America.|Shanghai Center for Mathematical Sciences, Fudan University, Shanghai, China.|Department of Biochemistry & Cellular and Molecular Biology, The University of Tennessee, Knoxville, Tennessee, United States of America.|Shanghai Center for Mathematical Sciences, Fudan University, Shanghai, China.|Department of Biochemistry & Cellular and Molecular Biology, The University of Tennessee, Knoxville, Tennessee, United States of America.