Nature and mechanism of the in vivo oligomerization of nucleoid protein H-NS.
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.
Stella
Stefano
S
Department of Biology MCA, Laboratory of Genetics, University of Camerino, Camerino (MC), Italy.
Spurio
Roberto
R
Falconi
Maurizio
M
Pon
Cynthia L
CL
Gualerzi
Claudio O
CO
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*
D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; C031908:H-NS protein, bacteria; D009841:Oligonucleotides; D012097:Repressor Proteins