Just a Flexible Linker? The Structural and Dynamic Properties of CBP-ID4 Revealed by NMR Spectroscopy

Biophys J. 2016 Jan 19;110(2):372-381. doi: 10.1016/j.bpj.2015.11.3516.

Abstract

Here, we present a structural and dynamic description of CBP-ID4 at atomic resolution. ID4 is the fourth intrinsically disordered linker of CREB-binding protein (CBP). In spite of the largely disordered nature of CBP-ID4, NMR chemical shifts and relaxation measurements show a significant degree of α-helix sampling in the protein regions encompassing residues 2-25 and 101-128 (1852-1875 and 1951-1978 in full-length CBP). Proline residues are uniformly distributed along the polypeptide, except for the two α-helical regions, indicating that they play an active role in modulating the structural features of this CBP fragment. The two helical regions are lacking known functional motifs, suggesting that they represent thus-far uncharacterized functional modules of CBP. This work provides insights into the functions of this protein linker that may exploit its plasticity to modulate the relative orientations of neighboring folded domains of CBP and fine-tune its interactions with a multitude of partners.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Motifs
  • Amino Acid Sequence
  • CREB-Binding Protein / chemistry*
  • Humans
  • Inhibitor of Differentiation Proteins / chemistry*
  • Molecular Dynamics Simulation*
  • Molecular Sequence Data
  • Protein Structure, Tertiary

Substances

  • ID4 protein, human
  • Inhibitor of Differentiation Proteins
  • CREB-Binding Protein