Characterization of the Streptococcus pneumoniae BgaC protein as a novel surface beta-galactosidase with specific hydrolysis activity for the Galbeta1-3GlcNAc moiety of oligosaccharides

Cited 36 time in scopus
Metadata Downloads
Title
Characterization of the Streptococcus pneumoniae BgaC protein as a novel surface beta-galactosidase with specific hydrolysis activity for the Galbeta1-3GlcNAc moiety of oligosaccharides
Author(s)
J K Jeong; Oh Suk Kwon; Yun Mi Lee; Doo-Byoung Oh; Jung Mi Lee; Seong Hun Kim; E H Kim; T N Le; D K Rhee; H A Kang
Bibliographic Citation
Journal of Bacteriology, vol. 191, no. 9, pp. 3011-3023
Publication Year
2009
Abstract
Streptococcus pneumoniae is a causative agent of high morbidity and mortality. Although sugar moieties have been recognized as ligands for initial contact with the host, only a few exoglycosidases have been reported to occur in S. pneumoniae. In this study, a putative beta-galactosidase, encoded by the bgaC gene of S. pneumoniae, was characterized for its enzymatic activity and virulence. The recombinant BgaC protein, expressed and purified from Escherichia coli, was found to have a highly regiospecific and sugar-specific hydrolysis activity for the Galbeta1-3-GlcNAc moiety of oligosaccharides. Interestingly, the BgaC hydrolysis activity was localized at the cell surface of S. pneumoniae, indicating that BgaC is expressed as a surface protein although it does not have a typical signal sequence or membrane anchorage motif. The surface localization of BgaC was further supported by immunofluorescence microscopy analysis using an antibody raised against BgaC and by a reassociation assay with fluorescein isothiocyanate-labeled BgaC. Although the bgaC deletion mutation did not significantly attenuate the virulence of S. pneumoniae in vivo, the bgaC mutant strain showed relatively low numbers of viable cells compared to the wild type after 24 h of infection in vivo, whereas the mutant showed higher colonization levels at 6 and 24 h postinfection in vivo. Our data strongly indicate for the first time that S. pneumoniae bgaC encodes a surface beta-galactosidase with high substrate specificity that is significantly associated with the infection activity of pneumococci.
ISSN
0021-9193
Publisher
Amer Soc Microb
DOI
http://dx.doi.org/10.1128/JB.01601-08
Type
Article
Appears in Collections:
Division of Bio Technology Innovation > SME Support Center > 1. Journal Articles
Division of Research on National Challenges > Environmental diseases research center > 1. Journal Articles
Jeonbuk Branch Institute > Microbial Biotechnology Research Center > 1. Journal Articles
Files in This Item:
  • There are no files associated with this item.


Items in OpenAccess@KRIBB are protected by copyright, with all rights reserved, unless otherwise indicated.