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
  • 1
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Science Ltd
    Molecular microbiology 45 (2002), S. 0 
    ISSN: 1365-2958
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology , Medicine
    Notes: In recent years, accumulating evidence for glycosylated bacterial proteins has overthrown an almost dogmatic belief that prokaryotes are not able to synthesize glycoproteins. Now it is widely accepted that eubacteria express glycoproteins. Although, at present, detailed information about glycosylation and structure–function relationships is available for only few eubacterial proteins, the variety of different components and structures observed already indicates that the variations in bacterial glycoproteins seem to exceed the rather limited display found in eukaryotes. Numerous virulence factors of bacterial pathogens have been found to be covalently modified with carbohydrate residues, thereby identifying these factors as true glycoproteins. In several bacterial species, gene clusters suggested to represent a general pro-tein glycosylation system have been identified. In other cases, genes encoding highly specific glycosyltransferases have been found to be directly linked with virulence genes. These findings raise interesting questions concerning a potential role of glycosylation in pathogenesis. In this review, we will therefore focus on protein glycosylation in Gram-negative bacterial pathogens.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Science, Ltd
    Molecular microbiology 40 (2001), S. 0 
    ISSN: 1365-2958
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology , Medicine
    Notes: The diffuse adherence of Escherichia coli strain 2787 (O126:H27) is mediated by the autotransporter adhesin AIDA-I (adhesin-involved-in-diffuse-adherence) encoded by the plasmid-borne aidA gene. AIDA-I exhibits an aberrant mobility in denaturing gel electrophoresis. Deletion of the open reading frame (ORF) A immediately upstream of aidA restores the predicted mobility of AIDA-I, but the adhesin is no longer functional. This indicates that the mature AIDA-I adhesin is post-translationally modified and the modification is essential for adherence function. Labelling with digoxigenin hydrazide shows AIDA-I to be glycosylated. Using carbohydrate composition analysis, AIDA-I contains exclusively heptose residues (ratio heptose:AIDA-I ≈19:1). The deduced amino acid sequence of the cytoplasmic open reading frame (ORF) A gene product shows homologies to heptosyltransferases. In addition, the modification was completely abolished in an ADP–glycero-manno-heptopyranose mutant. Our results provide direct evidence for glycosylation of the AIDA-I adhesin by heptoses with the ORF A gene product as a specific (mono)heptosyltransferase generating the functional mature AIDA-I adhesin. Consequently, the ORF A gene has been denoted ‘aah’ (autotransporter-adhesin-heptosyltransferase). Glycosylation by heptoses represents a novel protein modification in eubacteria.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Molecular microbiology 22 (1996), S. 0 
    ISSN: 1365-2958
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology , Medicine
    Notes: The AIDA-I adhesin known to be responsible for the diffuse adherence (DA) phenotype of the diarrhoea-genie Escherichia coli (DAEC) strain 2787 has been shown previously to be synthesized as a precursor protein and to undergo additional C-terminal processing. Here, the C-terminal processing of the AIDA-I precursor and the outer membrane topology of the cleaved C-terminal fragment, AIDAC, were investigated. By isolation of the cleaved AIDAC fragment and N-terminal sequencing, the C-terminal cleavage site was identified between Ser-846 and Ala-847 thereby indicating a molecular mass of 47.5 kDa for AIDAC. The correct processing to AIDA-I and AIDAC in OmpT, OmpP and DegP protease-deficient E. coli strains as well as in avirulent salmonellae and shigellae points to an autocatalytic cleavage mechanism. The cleaved AIDAC was localized in the outer membrane. A leader sequence-AIDAC fusion was efficiently routed to the outer membrane. Analysis by protease digestion, secondary-structure prediction and modelling, by comparison with structurally related bacterial proteins like the lgA1 protease from neisseria, the vacuolating toxin from Helicobacter pylori, and the VirG protein of Shigella flexneri, strongly indicates that AIDAC is present in the outer membrane as a β-barrel structure.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 1365-2958
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology , Medicine
    Notes: The adherence mechanisms of enteropathogenic Escherichia coli (EPEC) to epithelial cells are still not understood. To study the molecular basis of the diffuse adherence (DA) phenotype exhibited by diarrhoeagenic E. coli expressing classical EPEC serotypes we investigated strain 2787 (O126:H27) isolated from a case of infantile diarrhoea. A 6.0 kb plasmid-derrved DNA fragment mediates the DA phenotype and encodes the 100 kDa adhesin protein AIDA-I (adhesin involved in diffuse adherence). Sequencing of the entire fragment revealed two open reading frames which encoded proteins of 45 kDa and 132 kDa, respectively. The 132 kDa protein has been identified as an AIDA-I precursor protein. After cleavage of the signal sequence further processing at the C-terminus of the 132 kDa precursor leads to the mature ∼100 kDa AIDA-I. While the exact function of the cytopiasmic 45 kDa protein is not known, preliminary evidence indicates that it is necessary for the correct maturation of AIDA-I. The AIDA-l precursor exhibits significant homology with the virG(icsA) protein of Shigella flexneri which seems to be involved in the intercellular spread of invasive Shigella organisms.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Publication Date: 2003-12-01
    Print ISSN: 0966-842X
    Electronic ISSN: 1878-4380
    Topics: Biology
    Published by Cell Press
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Publication Date: 1990-04-01
    Print ISSN: 0014-2956
    Electronic ISSN: 1432-1033
    Topics: Biology , Chemistry and Pharmacology , Medicine
    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...