|Title||The Structural Basis for T-antigen Hydrolysis by Streptococcus pneumoniae A TARGET FOR STRUCTURE-BASED VACCINE DESIGN|
|Publication Type||Journal Article|
|Year of Publication||2008|
|Authors||Caines, MEC, Zhu, H, Vuckovic, M, Willis, LM, Withers, SG, Wakarchuk, WW, Strynadka, NCJ|
|Journal||JOURNAL OF BIOLOGICAL CHEMISTRY|
|Date Published||NOV 14|
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 angstrom 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.