1H, 13C, and 15N NMR assignments and global folding pattern of the RNA-binding domain of the human hnRNP C proteins.
The hnRNP C1 and C2 proteins are abundant nuclear proteins that bind avidly to heterogeneous nuclear RNAs (hnRNAs) and appear to be involved with pre-mRNA processing. The RNA-binding activity of the hnRNP C proteins is contained in the amino-terminal 94 amino acid RNA-binding domain (RBD) that is identical for these two proteins. We have obtained the 1H, 13C, and 15N NMR assignments for the RBD of the human hnRNP C proteins. The assignment process was facilitated by extensive utilization of three- and four-dimensional heteronuclear-edited spectra. Sequential assignments of the backbone resonances were made using a combination of 15N-edited 3D NOESY-HMQC, 3D TOCSY-HMQC, and 3D TOCSY-NOESY-HSQC as well as 3D HNCA, HNCO, and HCACO spectra. Side-chain resonances were assigned using 3D HCCH-COSY and 3D HCH-TOCSY spectra. Four-dimensional 13C/13C-edited NOESY and 13C/15N-edited NOESY experiments were used to unambigously resolve NOEs. The overall global folding pattern was established by calculating a set of preliminary structures using constraints derived from the sequential NOEs and a small number of long-range NOEs. The beta alpha beta-beta alpha beta domain structure exhibits an antiparallel beta-sheet with the conserved RNP 1 and RNP 2 sequences [Dreyfuss et al. (1988) Trends Biochem. Sci. 13, 86-91] located adjacent to one another as the two inner strands of the beta-sheet.
Wittekind
M
M
Macromolecular NMR Department, Bristol-Myers Squibb Pharmaceutical Research Institute, Princeton, New Jersey 08543-4000.
Görlach
M
M
Friedrichs
M
M
Dreyfuss
G
G
Mueller
L
L
D000595:Amino Acid Sequence; D001665:Binding Sites; D002247:Carbon Isotopes; D006859:Hydrogen; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009587:Nitrogen Isotopes; D011487:Protein Conformation; D012342:RNA, Small Nuclear / Q000378:metabolism*; D012261:Ribonucleoproteins / Q000737:chemistry* / Q000378:metabolism*; D017411:Ribonucleoproteins, Small Nuclear
D002247:Carbon Isotopes; D009587:Nitrogen Isotopes; D012342:RNA, Small Nuclear; D012261:Ribonucleoproteins; D017411:Ribonucleoproteins, Small Nuclear; D006859:Hydrogen