Linked Life Data

15101975

Source:http://linkedlifedata.com/resource/pubmed/id/15101975

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2004-4-22
pubmed:abstractText
Electron microscopy of isolated cell walls of the ancient bacterium Thermus thermophilus revealed that most of the peptidoglycan (PG) surface, apart from the septal region, was shielded against specific alphaPG antibodies. On the other hand, an antiserum raised against S-layer-attached cell wall fragments (alphaSAC) bound to most of the surface except for the septal regions. Treatments with alpha-amylase and pronase E made the entire cell wall surface uniformly accessible to alphaPG and severely decreased the binding of alphaSAC. We concluded that a layer of strongly bound secondary cell wall polymers (SCWPs) covers most of the cell wall surface in this ancient bacterium. A preliminary analysis revealed that such SCWPs constitute 14% of the cell wall and are essentially composed of sugars. Enzyme treatments of the cell walls revealed that SCWP was required in vitro for the binding of the S-layer protein through the S-layer homology (SLH) motif. The csaB gene was necessary for the attachment of the S-layer-outer membrane (OM) complex to the cell wall in growing cells of T. thermophilus. In vitro experiments confirmed that cell walls from a csaB mutant bound to the S-layer with a much lower affinity ( approximately 1/10) than that of the wild type. CsaB was found to be required for pyruvylation of components of the SCWP and for immunodetection with alpha-SAC antiserum. Therefore, the S-layer-OM complex of T. thermophilus binds to the cell wall through the SLH motif of the S-layer protein via a strong interaction with a highly immunogenic pyruvylated component of the SCWP. Immuno-cross-reactive compounds were detected with alphaSAC on cell walls of other Thermus spp. and in the phylogenetically related microorganism Deinococcus radiodurans. These results imply that the interaction between the SLH motif and pyruvylated components of the cell wall arose early during bacterial evolution as an ancestral mechanism for anchoring proteins and outer membranes to the cell walls of primitive bacteria.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0950-382X
pubmed:author
pubmed:issnType
Print
pubmed:volume
52
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
677-90
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
Binding to pyruvylated compounds as an ancestral mechanism to anchor the outer envelope in primitive bacteria.
pubmed:affiliation
Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid, Campus de Cantoblanco, 28049 Madrid, Spain.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't