This is the C-terminal domain found in mucin glycoproteins such as secreted protease of C1 esterase inhibitor from EHEC (StcE). This domain adopts a beta/gamma crystallin fold and has been shown to be dispensable for substrate binding. Furthermore, deletion analysis suggest that lack of the C-terminal resulted in impaired association with the cell surface [1].

1: Structural insight into the bacterial mucinase StcE essential to adhesion and immune evasion during enterohemorrhagic E. coli infection. Yu AC, Worrall LJ, Strynadka NC; Structure. 2012;20:707-717. PMID:22483117