Akademska digitalna zbirka SLovenije - logo
VSE knjižnice (vzajemna bibliografsko-kataložna baza podatkov COBIB.SI)
  • Transcription regulation of the colicin K cka gene reveals induction of colicin synthesis by differential responses to environmental signals
    Kuhar, Irena ; Žgur-Bertok, Darja
    Colicin-producing strains occur frequently in natural populations of Escherichia coli, and colicinogenicity seems to provide a competitive advantage in the natural habitat. A cka-IacZ fusion was used ... to study the regulation of expression of the colicin K structural gene. Expression is growth phase dependent, with high activity in the late stationary phase. Nutrient depletion induces the expression of cka due to an increase in ppGpp. Temperature is a strong signal for cka expression, since only basal-level activity was detected at 22oC. Mitomycin C induction demonstrates that cka expression is regulated to a lesser extent by the SOS response independently of ppGpp. Increased osmolarity induces a partial increase, while the global regulator integration host factor inhibits expression in the late stationary phase. Induction of cka was demonstrated to be independent of the cyclic AMP-Crp complex, carbon source, RpoS, Lrp, H-NS, pH, and short-chain fatty acids. In contrast to colicin E1, cka expression is independent of catabolite repression and is partially affected by anaerobiosis only upon SOS induction. These results indicate that while different colicins are expressed in responseto some common signals such as nutrient depletion, the expression of individual colicins could be further influenced by specific environmental cues.
    Vir: Journal of bacteriology. - ISSN 0021-9193 (Letn. 181, št. 23, 1999, str. 7373-7380)
    Vrsta gradiva - članek, sestavni del
    Leto - 1999
    Jezik - angleški
    COBISS.SI-ID - 11194585

vir: Journal of bacteriology. - ISSN 0021-9193 (Letn. 181, št. 23, 1999, str. 7373-7380)
loading ...
loading ...
loading ...