1H, 13C, and 15N NMR assignments and global folding pattern of the RNA-binding domain of the human hnRNP C proteins

Biochemistry. 1992 Jul 14;31(27):6254-65. doi: 10.1021/bi00142a013.

Abstract

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.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Binding Sites
  • Carbon Isotopes
  • Hydrogen
  • Magnetic Resonance Spectroscopy / methods
  • Models, Molecular
  • Molecular Sequence Data
  • Nitrogen Isotopes
  • Protein Conformation
  • RNA, Small Nuclear / metabolism*
  • Ribonucleoproteins / chemistry*
  • Ribonucleoproteins / metabolism*
  • Ribonucleoproteins, Small Nuclear

Substances

  • Carbon Isotopes
  • Nitrogen Isotopes
  • RNA, Small Nuclear
  • Ribonucleoproteins
  • Ribonucleoproteins, Small Nuclear
  • Hydrogen