The structural basis for T-antigen hydrolysis by Streptococcus pneumoniae: a target for structure-based vaccine design

J Biol Chem. 2008 Nov 14;283(46):31279-83. doi: 10.1074/jbc.C800150200. Epub 2008 Sep 10.


Streptococcus pneumoniae endo-alpha-N-acetylgalactosaminidase is a cell surface-anchored glycoside hydrolase from family GH101 involved in the breakdown of mucin type O-linked glycans. The 189-kDa mature enzyme specifically hydrolyzes the T-antigen disaccharide from extracellular host glycoproteins and is representative of a broadly important class of virulence factors that have remained structurally uncharacterized due to their large size and highly modular nature. Here we report a 2.9 angstroms resolution crystal structure that remarkably captures the multidomain architecture and characterizes a catalytic center unexpectedly resembling that of alpha-amylases. Our analysis presents a complete model of glycoprotein recognition and provides a basis for the structure-based design of novel Streptococcus vaccines and therapeutics.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antigens, Viral, Tumor / chemistry*
  • Antigens, Viral, Tumor / immunology*
  • Antigens, Viral, Tumor / metabolism
  • Catalytic Domain
  • Crystallography, X-Ray
  • Drug Design*
  • Hydrolysis
  • Models, Molecular
  • Protein Structure, Tertiary
  • Streptococcal Vaccines / immunology*
  • Streptococcus pneumoniae / chemistry*
  • Streptococcus pneumoniae / immunology*
  • Streptococcus pneumoniae / metabolism


  • Antigens, Viral, Tumor
  • Streptococcal Vaccines

Associated data

  • PDB/3ECQ