1H and 13C NMR assignments and molecular modelling of a minor groove DNA-binding peptide from the HMG-I protein.
The HMG-I subfamily of high mobility group (HMG) chromatin proteins consists of DNA-binding proteins that preferentially bind to stretches of A.T-rich sequence both in vitro and in vivo. Recently, members of the HMG-I family have been suggested to bind in vitro to the narrow minor groove of A.T-DNA by means of an 11 amino acid peptide binding domain (BD) which, because of its predicted structure, is called the 'A.T-hook motif' [Reeves, R. & Nissen, M. (1990) J. Biol. Chem. 265, 8573-8582], and would appear to be crescent-shaped. A BD peptide with 13 amino-acid residues was synthesized and examined by proton and carbon-13 nuclear magnetic resonance (NMR) spectroscopy. The peptide contains four proline residues, and on the basis of NOEs and 13C chemical shifts was found to exist in an all-trans conformation. Molecular modelling based on this result provides evidence for a dynamic equilibrium between turn-like conformations in solution, the most populated of which is likely to be an S-shaped conformer, on the basis of amide exchange data.
Evans
J N
JN
Department of Biochemistry and Biophysics, Washington State University, Pullman, USA.
Zajicek
J
J
Nissen
M S
MS
Munske
G
G
Smith
V
V
Reeves
R
R
D000595:Amino Acid Sequence; D001665:Binding Sites; D002247:Carbon Isotopes; D004268:DNA-Binding Proteins / Q000737:chemistry*; D006609:High Mobility Group Proteins / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry*; D017434:Protein Structure, Tertiary; D011522:Protons
D002247:Carbon Isotopes; D004268:DNA-Binding Proteins; D006609:High Mobility Group Proteins; D010455:Peptides; D011522:Protons