ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Escherichia coli  (2)
  • 1
    ISSN: 1617-4623
    Keywords: Escherichia coli ; DnaA ; Replication initiation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Overexpression of DnaA protein from a multicopy plasmid accompanied by a shift to 42°C causes initiation of one extra round of replication in a dnaA + strain grown in glycerol minimal medium. This extra round of replication does not lead to an extra cell division, such that cells contain twice the normal number of chromosomes.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1617-4623
    Keywords: Stringent control ; RNA polymerase ; Escherichia coli
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Previous studies on two Escherichia coli rpoB mutants, carrying single amino acid substitutions at approximate amino acid positions 736 and 906 in the β subunit, showed that these alterations in the RNA polymerase resulted in an apparent reduced response to valine-induced amino acid starvation in vivo and prevented ppGpp-mediated inhibition of transcriptional initiation at stable RNA promoters in vitro. These observations suggested that the mutations had altered either the ppGpp binding site or the promoter selectivity of the enzyme. The in vivo analysis presented here indicates that these mutants encode an RNA polymerase that responds normally to changes in the level of ppGpp; their apparent relaxedness is due to a reduced accumulation of ppGpp during isoleucine starvation. Thus, there is no indication that the mutations have altered ppGpp binding sites. These observations and the difference between in vitro and in vivo results can be explained by the assumption that the mutations produce an extended ppGpp-dependent pausing of RNA polymerase during the transcription of unstable RNA. Comparison of the vivo and in vitro effects of ppGpp on rrn transcription further suggests that these reflect different phenomena, although in both cases ppGpp inhibits rrn transcription.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...