title: Identification of an amino acid signature sequence predictive of protein G-inhibitable IgG3-binding activity in group-A streptococcal IgG-binding proteins.
abstract: Sequence comparison of six known group-A streptococcal IgG-binding proteins, sharing the common property of protein G-inhibitable IgG3-binding-activity, identified a highly conserved 35-amino-acid (aa) sequence (74-100% similarity) within an EQ-rich central conserved core region of each protein. A search of aa sequence databases identified four additional proteins with > 50% similarity to this consensus sequence. All of these proteins demonstrated protein G-inhibitable IgG3-binding activity. Taken together, these results identify a signature sequence that predicts the presence of a protein G-inhibitable IgG3-binding domain(s) in group-A streptococcal IgG-binding proteins.
authors.affiliation: Department of Microbiology, Medical College of Ohio, Toledo 43699-0008, USA.
authors.forename: T D
authors.initials: TD
authors.lastname: Pack
authors.forename: A
authors.initials: A
authors.lastname: Podbielski
authors.forename: M D
authors.initials: MD
authors.lastname: Boyle
mesh_terms: D000595:Amino Acid Sequence; D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins / Q000037:antagonists & inhibitors* / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D017124:Conserved Sequence / Q000235:genetics*; D005798:Genes, Bacterial / Q000235:genetics; D006801:Humans; D007074:Immunoglobulin G / Q000378:metabolism*; D008565:Membrane Proteins; D008969:Molecular Sequence Data; D011485:Protein Binding; D018085:Regulon / Q000235:genetics; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D013297:Streptococcus pyogenes / Q000737:chemistry / Q000235:genetics*
chemical_list: D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D002352:Carrier Proteins; C099983:Emm2 protein, Streptococcus pyogenes; C099984:Enn18 protein, Streptococcus pyogenes; C034284:IgG Fc-binding protein, Streptococcus; D007074:Immunoglobulin G; D008565:Membrane Proteins; C014689:streptococcal M protein