title: Cloning, expression, and characterization of a neuraminidase gene from Arcanobacterium pyogenes.
abstract: Arcanobacterium pyogenes is an opportunistic pathogen, associated with suppurative infections in domestic animals. In addition to pyolysin, a pore-forming, cholesterol-binding toxin, A. pyogenes expresses a number of putative virulence factors, including several proteases and neuraminidase activity. A 3,009-bp gene, nanH, was cloned and sequenced and conferred neuraminidase activity on an Escherichia coli host strain. The predicted 107-kDa NanH protein displayed similarity to a number of bacterial neuraminidases and contained the RIP/RLP motif and five copies of the Asp box motif found in all bacterial neuraminidases. Recombinant His-tagged NanH was found to have pH and temperature optima of 5.5 to 6.0 and 55 degrees C, respectively. Insertional deletion of the nanH gene resulted in the reduction, but not absence, of neuraminidase activity, indicating the presence of a second neuraminidase gene in A. pyogenes. NanH was localized to the A. pyogenes cell wall. A. pyogenes adhered to HeLa, CHO, and MDBK cells in a washing-resistant manner. However, the nanH mutant was not defective for adherence to epithelial cells. The role of NanH in host epithelial cell adherence may be masked by the presence of a second neuraminidase in A. pyogenes.
authors.affiliation: Department of Veterinary Science and Microbiology, The University of Arizona, Tucson, Arizona 85721, USA. jost@u.arizona.edu
authors.forename: B H
authors.initials: BH
authors.lastname: Jost
authors.forename: J G
authors.initials: JG
authors.lastname: Songer
authors.forename: S J
authors.initials: SJ
authors.lastname: Billington
mesh_terms: D000191:Actinomycetaceae / Q000201:enzymology* / Q000235:genetics / Q000502:physiology; D000595:Amino Acid Sequence; D000818:Animals; D000907:Antibodies, Bacterial / Q000276:immunology; D001422:Bacterial Adhesion; D001426:Bacterial Proteins; D001483:Base Sequence; D016466:CHO Cells; D003001:Cloning, Molecular; D006224:Cricetinae; D004269:DNA, Bacterial; D005260:Female; D015870:Gene Expression; D005798:Genes, Bacterial; D006041:Goats; D006367:HeLa Cells; D006639:Histidine / Q000235:genetics; D006801:Humans; D008969:Molecular Sequence Data; D016296:Mutagenesis; D009439:Neuraminidase / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000276:immunology; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid
chemical_list: D000907:Antibodies, Bacterial; D001426:Bacterial Proteins; D004269:DNA, Bacterial; D011993:Recombinant Fusion Proteins; D006639:Histidine; C430564:NanH protein, Arcanobacterium pyogenes; D009439:Neuraminidase