Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Molecular microbiology 14 (1994), S. 0 
    ISSN: 1365-2958
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology , Medicine
    Notes: The amount of the rate-limiting replication initiator protein RepR of plasmid p1P501 is negatively controlled by an antisense RNA (RNAIII) and a dispensable protein (CopR). Deletions or mutations in either component cause a 10-20-fold copy number increase. RNAIII induces transcription attenuation of the repR mRNA: the mode of CopR action remained unclear. To test the function of CopR, transcriptional fusions of promoters pI, pII and pIII with lacZ were integrated into the Bacillus subtilis chromosome. CopR and/or RepR were supplied in trans, and LacZ synthesis measured. The results show that CopR represses the repR promoter pII. Neither CopR nor RepR autoregulate their promoters. Gel mobility shift assays indicate that CopR binds to a 44 bp DNA fragment comprising the inverted repeat upstream of pII.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1617-4623
    Keywords: Bacillus subtilis ; Plasmid replication region ; Transcriptional analysis ; Promoter ; Terminator
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Derivatives of the conjugative streptococcal plasmid pIP501 replicate stably in Bacillus subtilis. The region essential for replication of plP501 has been narrowed down to a 2.2 kb DNA segment, the sequence of which has been determined. This region comprises two genes, copR and repR, proposed to be involved in copy control and replication. By in vitro and in vivo transcriptional analysis we characterized three active promoters, pII pII and pIII within this region. A putative fourth promoter (PTV) was neither active in vitro nor in vivo. We showed that copR is transcribed from promoter pI while the repR, gene is transcribed from promoter pII located just downstream of copR The pII transcript encompasses a 329 nucleotide (nt) long leader sequence. A counter transcript that was complementary to a major part of this leader was found to originate from a third promoter pIII The secondary structure of the counter transcript revealed several stem-loop regions. A regulatory function for this antisense RNA in the control of repR, expression is proposed. Comparative analysis of the replication regions of pAMβ 1 and pSM19035 suggested a similar organization of transcriptional units, suggesting that an antisense RNA is produced by these plasmids also.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1365-2958
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology , Medicine
    Notes: Antisense-RNAs have been investigated in detail over the past 20 years as the principal regulators in accessory DNA elements such as plasmids, phages and transposons. However, only a few examples of chromosomally encoded bacterial antisense RNAs were known. Meanwhile, ≈70 small non-coding RNAs from the Escherichia coli genome have been found, the functions of the majority of which remain to be elucidated. Only one systematic search has been performed for Gram-positive bacteria, so far. Here, we report the identification of a novel small (205 nt) non-translated RNA – SR1 – encoded in the Bacillus subtilis genome. SR1 was predicted by a computational approach and verified by Northern blotting. Knockout or overexpression of SR1 did not affect growth. SR1 was derepressed under conditions of gluconeogenesis, but repressed under glycolytic conditions. Two regulatory levels could be identified, one involving CcpA, the second, more important, involving the recently identified regulator CcpN.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Science Ltd
    Molecular microbiology 35 (2000), S. 0 
    ISSN: 1365-2958
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology , Medicine
    Notes: Antisense RNAs regulate plasmid replication by several different mechanisms. One of these mechanisms, transcriptional attenuation, was first described for the staphylococcal plasmid pT181, and later for the streptococcal plasmids pIP501 and pAMβ1. Previously, we performed detailed in vitro and in vivo analyses of the pIP501 system. Here, we present an in vitro analysis of the antisense system of plasmid pT181. The secondary structures of antisense and sense RNA species of different lengths were determined. Binding rate constants for sense/antisense RNA pairs were measured, and functional segments required for complex formation were determined. A single-round transcription assay was used for in vitro analysis of transcriptional attenuation. A comparison between pT181 and pIP501 revealed several differences; whereas a truncated derivative of pIP501 antisense RNA was sufficient for stable complex formation, both stem–loop structures of pT181-RNAI were required. In contrast to the sense RNA of pIP501, which showed an intrinsic propensity to terminate (30–50% in the absence of antisense RNA), the sense RNA of pT181 required antisense RNA for induced termination. Rate constants of formation of pT181 sense–antisense RNA complexes were similar to inhibition rate constants, in striking contrast to pIP501, in which inhibition occurred at least 10-fold faster than stable binding.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...