| Conformation of mononucleotides and dinucleoside monophosphates. P[H] and H[H] nuclear Overhauser effects Biophysical Journal, Volume 24, Issue 3, 1 December 1978, Pages 833-848 P.A. Hart Abstract The phosphorus-proton nuclear Overhauser effect (NOE) was used to investigate the quantitative distribution of rotamers about the C3'--O3' bond (phi') of 3'-AMP and 2',3'-cyclic-CMP and the C4'--C5', C5'--O5' bonds (psi, phi) of 5'-AMP. Phosphorus-proton and proton-proton NOE's were used to provide a qualitative insight into the backbone conformation and the glycosyl angle torsions of adenosylyl-(3' leads to 5')-adenosine (ApA). The major psi rotamer in 5'-AMP is the 60 degree (gg) form, while the major phi rotamer is the 180 degrees (g'g') form. The constrained model, 2',3'-cyclic-CMP, manifests the C3'endo furanose pucker predominantly. The results from these two models are consistent with nuclear magnetic resonance (NMR) J coupling analyses. The phi; distribution of 3'-AMP is dominated (77%) by the 180 degrees g- rotamer. The 3'-AMP results are consistent with phosphorus-hydrogen coupling constant analyses, but do not accord with phosphorus-carbon coupling constant results. The phosphorus-proton NOE reveals that the phosphorus of ApA occupies a region of conformation space not seen in 5'-AMP. The proton-proton NOE on APA shows a significant portion of syn rotamer in both X distributions and detects a cross-purine ring interaction consistent with base stacking known to exist in this system. Abstract | PDF (881 kb) |
| The Focal Adhesion Targeting Domain of Focal Adhesion Kinase Contains a Hinge Region that Modulates Tyrosine 926 Phosphorylation Structure, Volume 12, Issue 5, 1 May 2004, Pages 881-891 Kirk C Prutzman, Guanghua Gao, Michelle L King, Vidhya V Iyer, Geoffrey A Mueller, Michael D Schaller and Sharon L Campbell Summary The focal adhesion targeting (FAT) domain of focal adhesion kinase (FAK) is critical for recruitment of FAK to focal adhesions and contains tyrosine 926, which, when phosphorylated, binds the SH2 domain of Grb2. Structural studies have shown that the FAT domain is a four-helix bundle that exists as a monomer and a dimer due to domain swapping of helix 1. Here, we report the NMR solution structure of the avian FAT domain, which is similar in overall structure to the X-ray crystal structures of monomeric forms of the FAT domain, except that loop 1 is longer and less structured in solution. Residues in this region undergo temperature-dependent exchange broadening and sample aberrant phi and psi angles, which suggests that this region samples multiple conformations. We have also identified a mutant that dimerizes ∼8 fold more than WT FAT domain and exhibits increased phosphorylation of tyrosine 926 both in vitro and in vivo. Summary | Full Text | PDF (560 kb) |
| The solution structure of VAT-N reveals a ‘missing link’ in the evolution of complex enzymes from a simple βαββ element Current Biology, Volume 9, Issue 20, 21 October 1999, Pages 1158-1168 M. Coles, T. Diercks, J. Liermann, A. Gröger, B. Rockel, W. Baumeister, K.K. Koretke, A. Lupas, J. Peters and H. Kessler Summary Our results suggest that VAT-N is a precursor of the aspartic proteinases that has acquired peptide-binding activity while remaining proteolytically incompetent. We propose that the binding site of the protein is similar to that of aspartic proteinases, in that it lies between the psi-loops of the amino-terminal β-barrel and that it coincides with a crescent-shaped band of positive charge extending across the upper face of the molecule. Summary | Full Text | PDF (223 kb) |
Copyright © 1980 The Biophysical Society. All rights reserved.
Biophysical Journal, Volume 32, Issue 2, 807-836, 1 November 1980
doi:10.1016/S0006-3495(80)85018-1
Research Article
M.C. Kuo and W.A. Gibbons
The following interproton distances are reported for the decapeptide tyrocidine A in solution: (a) r(phi) distances between NH(i) and H alpha (i), (b) r(psi) distances between NH (i + 1) and H alpha (i), (c) r(phi psi) distances between NH(i + 1) and NH(i), (d) NH in equilibrium NH transannular distances, (e) H alpha in equilibrium H alpha transannular distances, (f) r x 1 distances between H alpha and H beta protons, (g) NH(i) in equilibrium H beta (i) distances, (h) NH (i + 1) in equilibrium H beta (i) distances, (i) carboxamide-backbone protons and carboxamide-side chain proton distances, (j) side chain proton-side chain proton distances. The procedures for distance calculations were: NOE ratios and calibration distances, sigma ratios and calibration distances, and correlation times and sigma parameters. The cross-relaxation parameters were obtained from the product, say, of NOE 1 leads to 2 and the monoselective relaxation rate of proton 2; the NOEs were measured by NOE difference spectroscopy. The data are consistent with a type I beta-turn/ type II' beta-turn/ approximately antiparallel beta-pleated sheet conformation of tyrocidine A in solution and the NOEs, cross-relaxation parameters, and interproton distances serve as distinguishing criteria for beta-turn and beta-pleated sheet conformations. It should be borne in mind that measurement of only r phi and r psi distances for a decapeptide only defines the ( phi, psi)-space in terms of 4(10) possible conformations; the distances b-j served to reduce the degeneracy in possible (phi, psi)-space to one tyrocidine A conformation. The latter conformation is consistent with that derived from scalar coupling constants, hydrogen bonding studies, and proton-chromophore distance measurement, and closely resembles the conformation of gramicidin S.