Identification of the glycosaminoglycan-binding site on the glycoprotein E(rns) of bovine viral diarrhoea virus by site-directed mutagenesis.
Bovine viral diarrhoea virus (BVDV) envelope glycoprotein E(rns) interacts with highly sulphated heparin-like glycosaminoglycans (GAGs) located on the cell surface as an early step in virus infection of cells. Site-directed mutagenesis of recombinant E(rns) was undertaken and analysis of mutants by heparin-affinity chromatography and cell surface binding showed that a cluster of basic amino acids (480KKLENKSK487) near the C terminus of E(rns) was essential for binding. Mutants with amino acid substitutions of lysine residues 481 and 485 in E(rns) reduced the binding of E(rns) to immobilized heparin and cellular GAGs but retained ribonuclease activity. In contrast to normal E(rns), E(rns) that was unable to bind to cells also failed to inhibit BVDV infection of cells when the cells were pre-incubated with E(rns). It is proposed that the cluster of basic residues (480KKLENKSK487) localized at the C-terminal end of E(rns) constitutes a GAG-binding site.
Division of Molecular Biology, Institute for Animal Health, Compton Laboratory, Compton, Newbury RG20 7NN, UK1.
Munir
M
Iqbal
Division of Molecular Biology, Institute for Animal Health, Compton Laboratory, Compton, Newbury RG20 7NN, UK1.
John W
JW
McCauley
D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D002417:Cattle; D002462:Cell Membrane / Q000378:metabolism; D002478:Cells, Cultured; D016384:Consensus Sequence; D001908:Diarrhea Viruses, Bovine Viral / Q000378:metabolism*; D015683:Gene Products, gag / Q000378:metabolism; D006023:Glycoproteins / Q000378:metabolism*; D006025:Glycosaminoglycans / Q000378:metabolism*; D007313:Insecta; D008297:Male; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D011994:Recombinant Proteins / Q000378:metabolism; D014759:Viral Envelope Proteins / Q000235:genetics / Q000378:metabolism*; D014779:Virus Replication
D015683:Gene Products, gag; D006023:Glycoproteins; D006025:Glycosaminoglycans; D011994:Recombinant Proteins; D014759:Viral Envelope Proteins