GAGBD is a domain on the surface antigen of the swine pathogen Streptococcus suis and related species. This domain expresses three clusters of basic residues, largely lysines, that are critical for heparin-binding and cell adhesion during bacterium-host cell adhesion. The GAGBD domain binds to the host cell surface glycosaminoglycans or GAGs of the Streptococcus [1].

1: Molecular mechanism by which surface antigen HP0197 mediates host cell attachment in the pathogenic bacteria Streptococcus suis. Yuan ZZ, Yan XJ, Zhang AD, Chen B, Shen YQ, Jin ML; J Biol Chem. 2013;288:956-963. PMID:23184929