Library

X
feed icon rss

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
    Structural basis for broad DNA-specificity in integron recombination (2006)
    [s.l.] : Nature Publishing Group
    Nature 440 (2006), S. 1157-1162 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Lateral DNA transfer—the movement of genetic traits between bacteria—has a profound impact on genomic evolution and speciation. The efficiency with which bacteria incorporate genetic information reflects their capacity to adapt to changing environmental conditions. Integron integrases are proteins ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/nature04643
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Bacterial resistance evolution by recruitment of super-integron gene cassettes (2002)
    Oxford, UK : Blackwell Science Ltd
    Molecular microbiology 43 (2002), S. 0 
    Details
    ISSN: 1365-2958
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology , Medicine
    Notes: The capture and spread of antibiotic resistance determinants by integrons underlies the rapid evolution of multiple antibiotic resistance among diverse Gram-negative clinical isolates. The association of multiple resistance integrons (MRIs) with mobile DNA elements facilitates their transit across phylogenetic boundaries and augments the potential impact of integrons on bacterial evolution. Recently, ancestral chromosomal versions, the super-integrons (SIs), were found to be genuine components of the genomes of diverse bacterial species. SIs possess evolutionary characteristics and stockpiles of adaptive functions, including cassettes related to antibiotic resistance determinants previously characterized in clinical isolates, which suggest that MRIs and their resistance genes were originally recruited from SIs and their pool of amassed genes. However, the recombination activity of integrons has never been demonstrated in a bacterium other than Escherichia coli. We introduced a naturally occurring MRI (TpR, SulR) on a conjugative plasmid into Vibrio cholerae, a species known to harbour a SI. We show that MRIs can randomly recruit genes directly from the cache of SI cassettes. By applying a selective constraint for the development of antibiotic resistance, we demonstrate bacterial resistance evolution through the recruitment a novel, but phenotypically silent, chloramphenicol acetyltransferase gene from the V. cholerae SI and its precise insertion into the MRI. The resulting resistance profile (CmR, TpR, SulR) could then be disseminated by conjugation to other clinically relevant pathogens at high frequency. These results demonstrate that otherwise phenotypically sensitive strains may still be a genetic source for the evolution of resistance to clinically relevant antibiotics through integron-mediated recombination events.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1365-2958.2002.02861.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Adaptive eradication of methionine and cysteine from cyanobacterial light-harvesting proteins (1989)
    [s.l.] : Nature Publishing Group
    Nature 341 (1989), S. 245-248 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Phycobilisomes, the light-harvesting complexes of cyano-bacteria, account for up to 60% of the soluble protein content in these organisms4. The overall design of the phycobilisome consists of a hemidisk of six rods radiating fanwise from a central core5'6. Phycobilisomes are made of three principal ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/341245a0
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Photoregulation of gene expression in the filamentous cyanobacterium Calothrix sp. PCC 7601: light-harvesting complexes and cell differentiation (1988)
    Springer
    Photosynthesis research 18 (1988), S. 99-132 
    Details
    ISSN: 1573-5079
    Keywords: Calothrix sp. PCC 7601 ; gas vesicles ; hormogonia ; photoregulation ; phycobiliproteins ; phycobilisomes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Light plays a major role in many physiological processes in cyanobacteria. In Calothrix sp. PCC 7601, these include the biosynthesis of the components of the light-harvesting antenna (phycobilisomes) and the differentiation of the vegetative trichomes into hormogonia (short chains of smaller cells). In order to study the molecular basis for the photoregulation of gene expression, physiological studies have been coupled with the characterization of genes involved either in the formation of phycobilisomes or in the synthesis of gas vesicles, which are only present at the hormogonial stage. In each system, a number of genes have been isolated and sequenced. This demonstrated the existence of multigene families, as well as of gene products which have not yet been identified biochemically. Further studies have also established the occurrence of both transcriptional and post-transcriptional regulation. The transcription of genes encoding components of the phycobilisome rods is light-wavelength dependent, while translation of the phycocyanin genes may require the synthesis of another gene product irrespective of the light regime. In this report, we propose two hypothetical models which might be part of the complex regulatory mechanisms involved in the formation of functional phycobilisomes. On the other hand, transcription of genes involved in the gas vesicles formation (gvp genes) is turned on during hormogonia differentiation, while that of phycobiliprotein genes is simultaneously turned off. In addition, and antisense RNA which might modulate the translation of the gvp mRNAs is synthezised.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00042981
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    A multigene family in Calothrix sp. PCC 7601 encodes phycocyanin, the major component of the cyanobacterial light-harvesting antenna (1988)
    Springer
    Molecular genetics and genomics 211 (1988), S. 296-304 
    Details
    ISSN: 1617-4623
    Keywords: Complementary chromatic adaptation ; Gene expression ; Photoregulation ; Phycobilisome ; Recombinant DNA
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary In cyanobacteria, light is harvested by phycobilisomes which are essentially made up of chromophoric proteins called phycobiliproteins. We have characterized two gene clusters (cpcB1, cpcA1 and cpcB3, cpcA3) each encoding the two subunits of phycocyanin (βPC and αPC, respectively), one of the major phycobiliproteins in Calothrix 7601. Downstream from the gene encoding the PCα subunit in cluster 1, an open reading frame was found, cpcE1. These genes are organized in two transcriptional units, namely: cpcB3 A3 and cpcB1 A1 E1. All these genes are transcribed whatever the chromatic light received during cell growth. Consequently, although only one type of “constitutive” PC has been biochemically characterized, we have demonstrated that there are two cpc operons “constitutively” transcribed in this strain. With the previously described red light “inducible” cpcB2 A2 operon, there are three copies of the PC encoding genes in Calothrix 7601. The significance of this newly described multigene family in cyanobacteria is discussed. We have also mapped the 5′ and 3′ termini of the major transcript from the cpc1 operon. Analysis of the 5′ untranslated region of this transcript has revealed alternative secondary structures which are proposed to play a role in the regulation of the expression of this operon.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00330607
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...