This is the N-terminal domain found in Streptococcus pneumoniae endo-alpha-N-acetylgalactosaminidase (EC:3.2.1.97) , a cell surface-anchored glycoside hydrolase from family GH101 involved in the breakdown of mucin type O-linked glycans. This is a twisted beta-sandwich domain composed of two sheets of six and seven antiparallel beta-strands. The domain appears to be missing the extended metal and carbohydrate-binding loops [1].

1: The structural basis for T-antigen hydrolysis by Streptococcus pneumoniae: a target for structure-based vaccine design. Caines ME, Zhu H, Vuckovic M, Willis LM, Withers SG, Wakarchuk WW, Strynadka NC; J Biol Chem. 2008;283:31279-31283. PMID:18784084