3D C(CC)H TOCSY EXPERIMENT FOR ASSIGNING PROTONS AND CARBONS IN UNIFORMLY C-13-LABELED AND SELECTIVELY H-2-LABELED RNA

We have prepared RNAs uniformly C-13-labeled in the ribose ring and wi th the H3', H4', H5'/H5'' protons specifically replaced with deuterons (3', 4', 5'/5''-H-2-C-13, termed d4-C-13 ribose), which offers the ad vantage of spectral simplification without sacrifice of sensitivity fo r the remaining protons. A 3D C(CC)H. TOCSY experiment that uses a com bination of cross-polarization transfer and deuterium decoupling impro ves the transfer of magnetization around the ribose ring and facilitat es assignment of all ribose carbons and H1' and H2' protons in a 30-nu cleotide RNA from HIV-2. These and other combinations of labeling and pulse sequence methodology should prove invaluable for the study of la rge RNAs, RNA-ligand, and RNA-protein complexes. (C) 1998 Academic Pre ss.