title: The yhhP gene encoding a small ubiquitous protein is fundamental for normal cell growth of Escherichia coli.
abstract: H-NS is a major constituent of the Escherichia coli nucleoid, whereas sigmaS is a stress-induced sigma factor. An hns null mutation affects the cellular content of sigmaS in such a way that a remarkable accumulation of sigmaS is observed in the logarithmic growth phase, which results in enhanced expression of a number of sigmaS-dependent genes, including the katE gene. We isolated an extragenic mutation that affects the expression of the katE-lacZ fusion gene in the deltahns background. The relevant gene was identified as yhhP, which encodes a small polypeptide of 81 amino acids. Lesion of this gene seemed to affect the stability of sigmaS. A deletion analysis of yhhP revealed that this small protein plays a fundamental role in the general physiology of E. coli. The yhhP-deficient cell is not capable of growing in standard laboratory rich medium (i.e., Luria broth), resulting in the formation of filamentous cells. Homologs of this intriguing protein occur in a wide variety of bacterial species, including archaeal species.
authors.affiliation: Laboratory of Molecular Microbiology, School of Agriculture, Nagoya University, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Yamashino
authors.forename: M
authors.initials: M
authors.lastname: Isomura
authors.forename: C
authors.initials: C
authors.lastname: Ueguchi
authors.forename: T
authors.initials: T
authors.lastname: Mizuno
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D029968:Escherichia coli Proteins; D015964:Gene Expression Regulation, Bacterial; D007700:Kinetics; D008969:Molecular Sequence Data; D016296:Mutagenesis; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D015183:Restriction Mapping; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D012808:Sigma Factor / Q000096:biosynthesis
chemical_list: D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; C031908:H-NS protein, bacteria; D011993:Recombinant Fusion Proteins; D012808:Sigma Factor; C111946:SirA protein, E coli; C069567:sigma factor KatF protein, Bacteria