title: Low resolution structure of interleukin-1 beta in solution derived from 1H-15N heteronuclear three-dimensional nuclear magnetic resonance spectroscopy.
abstract: A low resolution solution structure of the cytokine interleukin-1 beta, a 153 residue protein of molecular weight 17,400, has been determined on the basis of 446 nuclear Overhauser effect (NOE) derived approximate interproton distance restraints involving solely NH, C alpha H and C beta H protons, supplemented by 90 distance restraints for 45 hydrogen bonds, and 79 phi torsion angle restraints. With the exception of 27 C alpha H-C alpha H NOEs, all the NOEs were assigned from a three-dimensional 1H-1H NOE 15N-1H heteronuclear multiple quantum coherence (HMQC) spectrum. The torsion angle restraints were obtained from accurate 3JHN alpha coupling constants measured from a HMQC-J spectrum, while the hydrogen bonds were derived from a qualitative analysis of the NOE, coupling constant and amide exchange data. A total of 20 simulated annealing (SA) structures was computed using the hybrid distance geometry-dynamical simulated annealing method. The solution structure of IL-1 beta comprises 12 beta-strands arranged in three pseudo-symmetrical topological units (each consisting of 5 anti-parallel beta-strands), joined by turns, short loops and long loops. The core of the structure, which is made up of the 12 beta-strands, together with the turns joining strands I and II, strands VIII and IX and strands X and XI, is well determined with a backbone atomic root-mean-square (r.m.s.) distribution about the mean co-ordinate positions of 1.2(+/- 0.1) A. The loop conformations, on the other hand, are poorly determined by the current data. A comparison of the core of the low resolution solution structure of IL-1 beta with that of the X-ray structure indicates that they are similar, with a backbone atomic r.m.s. difference of only 1.5 A between the co-ordinates of the restrained minimized mean of the SA structures and the X-ray structure.
authors.affiliation: Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892.
authors.forename: G M
authors.initials: GM
authors.lastname: Clore
authors.forename: P C
authors.initials: PC
authors.lastname: Driscoll
authors.forename: P T
authors.initials: PT
authors.lastname: Wingfield
authors.forename: A M
authors.initials: AM
authors.lastname: Gronenborn
mesh_terms: D006859:Hydrogen; D007375:Interleukin-1; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008958:Models, Molecular; D009587:Nitrogen Isotopes; D011487:Protein Conformation; D012996:Solutions; D014961:X-Ray Diffraction
chemical_list: D007375:Interleukin-1; D009587:Nitrogen Isotopes; D012996:Solutions; D006859:Hydrogen