title: Protein oligomers studied by solid-state NMR--the case of the full-length nucleoid-associated protein histone-like nucleoid structuring protein.
abstract: Members of the histone-like nucleoid structuring protein (H-NS) family play roles both as architectural proteins and as modulators of gene expression in Gram-negative bacteria. The H-NS protein participates in modulatory processes that respond to environmental changes in osmolarity, pH, or temperature. H-NS oligomerization is essential for its activity. Structural models of different truncated forms are available. However, high-resolution structural details of full-length H-NS and its DNA-bound state have largely remained elusive. We report on progress in characterizing the biologically active H-NS oligomers with solid-state NMR. We compared uniformly ((13)C,(15)N)-labeled ssNMR preparations of the isolated N-terminal region (H-NS 1-47) and full-length H-NS (H-NS 1-137). In both cases, we obtained ssNMR spectra of good quality and characteristic of well-folded proteins. Analysis of the results of 2D and 3D (13)C-(13)C and (15)N-(13)C correlation experiments conducted at high magnetic field led to assignments of residues located in different topological regions of the free full-length H-NS. These findings confirm that the structure of the N-terminal dimerization domain is conserved in the oligomeric full-length protein. Small changes in the dimerization interface suggested by localized chemical shift variations between solution and solid-state spectra may be relevant for DNA recoginition.
authors.affiliation: Bijvoet Center for Biomolecular Research, Utrecht University, The Netherlands.
authors.forename: Marie
authors.initials: M
authors.lastname: Renault
authors.forename: Jesús
authors.initials: J
authors.lastname: García
authors.forename: Tiago N
authors.initials: TN
authors.lastname: Cordeiro
authors.forename: Marc
authors.initials: M
authors.lastname: Baldus
authors.forename: Miquel
authors.initials: M
authors.lastname: Pons
mesh_terms: D001665:Binding Sites; D004926:Escherichia coli; D029968:Escherichia coli Proteins / Q000737:chemistry*; D036781:Fimbriae Proteins / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D054730:Protein Interaction Domains and Motifs; D020836:Protein Structure, Quaternary; D017433:Protein Structure, Secondary
chemical_list: D029968:Escherichia coli Proteins; C529458:FimG protein, E coli; D036781:Fimbriae Proteins