1. Department
of Biochemistry, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061, United States
2. Department
of Biochemistry and Molecular Biology, Oregon Health and Science University, 3181 Southwest Sam Jackson Park Road, Portland, Oregon 97239-3098, United States
3. Department
of Chemistry, Portland State University, 1719 Southwest 10th Avenue, Portland, Oregon 97201, United States