Linked Life Data

11044451

Source:http://linkedlifedata.com/resource/pubmed/id/11044451

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2001-5-23
pubmed:abstractText
Clumping factor A (ClfA) is a cell surface-associated protein of Staphylococcus aureus that promotes binding of this pathogen to both soluble and immobilized fibrinogen (Fg). Previous studies have localized the Fg-binding activity of ClfA to residues 221-559 within the A region of this protein. In addition, the C-terminal part of the A region (residues 484-550) has been implicated as being important for Fg binding. In this study, we further investigate the involvement of this part of ClfA in the interaction of this protein with Fg. Polyclonal antibodies generated against a recombinant protein encompassing residues 500-559 of the A region inhibited the interaction of both S. aureus and recombinant ClfA with immobilized Fg in a dose-dependent manner. Using site-directed mutagenesis, two adjacent residues, Glu(526) and Val(527), were identified as being important for the activity of ClfA. S. aureus expressing ClfA containing either the E526A or V527S substitution exhibited a reduced ability to bind to soluble Fg and to adhere to immobilized Fg. Furthermore, bacteria expressing ClfA containing both substitutions were almost completely defective in Fg binding. The E526A and V527S substitutions were also introduced into recombinant ClfA (rClfA-(221-559)) expressed in Escherichia coli. The single mutant rClfA-(221-559) proteins showed a significant reduction in affinity for both immobilized Fg and a synthetic fluorescein-labeled C-terminal gamma-chain peptide compared with the wild-type protein, whereas the double mutant rClfA-(221-559) protein was almost completely defective in binding to either species. Substitution of Glu(526) and/or Val(527) did not appear to alter the secondary structure of rClfA-(221-559) as determined by far-UV circular dichroism spectroscopy. These data suggest that the C terminus of the A region may contain at least part of the Fg-binding site of ClfA and that Glu(526) and Val(527) may be involved in ligand recognition.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
26
pubmed:volume
276
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2466-73
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2001
pubmed:articleTitle
Identification of residues in the Staphylococcus aureus fibrinogen-binding MSCRAMM clumping factor A (ClfA) that are important for ligand binding.
pubmed:affiliation
Department of Microbiology, Moyne Institute of Preventive Medicine, Trinity College, Dublin 2, Ireland.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't