Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1994-9-8
pubmed:abstractText
The filamentous hemagglutinin (FHA) of Bordetella pertussis is an adhesin that binds the bacteria to cells of the respiratory epithelium in whooping-cough infections. Mature FHA is a 220 kDa secretory protein that is highly immunogenic and has been included in acellular vaccines. We have investigated its structure by combining electron microscopy and circular dichroism spectroscopy (CD) with computational analysis of its amino acid sequence. The FHA molecule is 50 nm in length and has the shape of a horseshoe nail: it has a globular head that appears to consist of two domains; a 35 nm-long shaft that averages 4 nm in width, but tapers slightly from the head end; and a small, flexible, tail. Mass measurements by scanning transmission electron microscopy establish that FHA is a monomer. Its sequence contains two regions of tandem 19-residue pseudo-repeats: the first, of 38 cycles, starts at residue 344; the second, of 13 cycles, starts at residue 1440. The repeat motifs are predicted to consist of short beta-strands separated by beta-turns, and secondary structure measurements by CD support this prediction. We propose a hairpin model for FHA in which the head is composed of the terminal domains; the shaft consists mainly of the repeat regions conformed as amphipathic, hyper-elongated beta-sheets, with their hydrophobic faces apposed; and the tail is composed of the intervening sequence. Further support for the model was obtained by immuno-labeling electron microscopy. The 19-residue repeats of FHA have features in common with the leucine-rich repeats (LRRs) that are present in many eukaryotic proteins, including some adhesion factors. The model is also compared with the two other classes of filamentous proteins that are rich in beta-structure, i.e. viral adhesins and two beta-helical secretory proteins. Our proposed structure implies how the functionally important adhesion sites and epitopes of FHA are distributed: its tripeptide (RGD) integrin-binding site is assigned to the tail; the putative hemagglutination site forms part of the head; and two classes of immunodominant epitopes are assigned to opposite ends of the molecule. Possible mechanisms are discussed for two modes of FHA-mediated adhesion.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0022-2836
pubmed:author
pubmed:issnType
Print
pubmed:day
5
pubmed:volume
241
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
110-24
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:7519681-Adhesins, Bacterial, pubmed-meshheading:7519681-Amino Acid Sequence, pubmed-meshheading:7519681-Amino Acids, pubmed-meshheading:7519681-Antigens, Bacterial, pubmed-meshheading:7519681-Bacterial Proteins, pubmed-meshheading:7519681-Bordetella pertussis, pubmed-meshheading:7519681-Chymotrypsin, pubmed-meshheading:7519681-Consensus Sequence, pubmed-meshheading:7519681-Epitopes, pubmed-meshheading:7519681-Hemagglutinins, pubmed-meshheading:7519681-Image Processing, Computer-Assisted, pubmed-meshheading:7519681-Microscopy, Electron, pubmed-meshheading:7519681-Microscopy, Electron, Scanning Transmission, pubmed-meshheading:7519681-Models, Biological, pubmed-meshheading:7519681-Molecular Sequence Data, pubmed-meshheading:7519681-Molecular Weight, pubmed-meshheading:7519681-Protein Conformation, pubmed-meshheading:7519681-Protein Structure, Secondary, pubmed-meshheading:7519681-Repetitive Sequences, Nucleic Acid, pubmed-meshheading:7519681-Sequence Homology, Amino Acid, pubmed-meshheading:7519681-Virulence Factors, Bordetella
pubmed:year
1994
pubmed:articleTitle
Filamentous hemagglutinin of Bordetella pertussis. A bacterial adhesin formed as a 50-nm monomeric rigid rod based on a 19-residue repeat motif rich in beta strands and turns.
pubmed:affiliation
Laboratory of Structural Biology, National Institute for Arthritis, Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD 20892.
pubmed:publicationType
Journal Article