title: Nature and mechanism of the in vivo oligomerization of nucleoid protein H-NS.
abstract: Two types of two-hybrid systems demonstrate that the transcriptional repressor, nucleoid-associated protein H-NS (histone-like, nucleoid structuring protein) forms dimers and tetramers in vivo, the latter being the active form of the protein. The H-NS 'protein oligomerization' domain (N-domain) is unable to oligomerize in the absence of the intradomain linker while the 'DNA-binding' C-domain clearly displays a protein-protein interaction capacity, which contributes to H-NS tetramerization and which is lost following Pro115 mutation. Linker deletion or substitution with KorB linker abolishes H-NS oligomerization. A model describing H-NS dimerization and tetramerization based on all available data and suggesting the existence in the tetramer of a bundle of four alpha-helices, each contributed by an H-NS monomer, is presented.
authors.affiliation: Department of Biology MCA, Laboratory of Genetics, University of Camerino, Camerino (MC), Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Stella
authors.forename: Roberto
authors.initials: R
authors.lastname: Spurio
authors.forename: Maurizio
authors.initials: M
authors.lastname: Falconi
authors.forename: Cynthia L
authors.initials: CL
authors.lastname: Pon
authors.forename: Claudio O
authors.initials: CO
authors.lastname: Gualerzi
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D019281:Dimerization; D004926:Escherichia coli; D008958:Models, Molecular; D009154:Mutation / Q000235:genetics; D009841:Oligonucleotides; D010957:Plasmids / Q000235:genetics; D017434:Protein Structure, Tertiary; D012097:Repressor Proteins / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; C031908:H-NS protein, bacteria; D009841:Oligonucleotides; D012097:Repressor Proteins