H-NS and H-NS-like proteins in Gram-negative bacteria and their multiple role in the regulation of bacterial metabolism.
In Escherichia coli, the H-NS protein plays an important role in the structure and the functioning of bacterial chromosome. A homologous protein has also been identified in several enteric bacteria and in closely related organisms such as Haemophilus influenzae. To get information on their structure and their function, we identified H-NS-like proteins in various microorganisms by different procedures. In silico analysis of their amino acid sequence and/or in vivo experiments provide evidence that more than 20 proteins belong to the same class of regulatory proteins. Moreover, large scale technologies demonstrate that, at least in E. coli, the loss of motility in hns mutants results from a lack of flagellin biosynthesis, due to the in vivo repression of flagellar gene expression. In contrast, several genes involved in adaptation to low pH are strongly induced in a H-NS deficient strain, resulting in an increased resistance to acidic stress. Finally, expression profiling and phenotypic analysis suggest that, unlike H-NS, its paralogous protein StpA does not play any role in these processes.
Unité de Régulation de l' Expression Génétique, Institut Pasteur, 28, rue du Dr.-Roux, 75724 Paris cedex 15, France. phbertin@pasteur.fr
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Bertin
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Hommais
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Krin
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Soutourina
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Tendeng
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Derzelle
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Danchin
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000502:physiology*; D001483:Base Sequence; D017124:Conserved Sequence; D004268:DNA-Binding Proteins / Q000502:physiology*; D016208:Databases, Factual; D020869:Gene Expression Profiling; D015698:Genomic Library; D006090:Gram-Negative Bacteria / Q000378:metabolism*; D008969:Molecular Sequence Data; D016296:Mutagenesis; D020411:Oligonucleotide Array Sequence Analysis; D010641:Phenotype; D011487:Protein Conformation; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid
D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; C031908:H-NS protein, bacteria