Ths presumed domain is found in the CshA protein from Streptococcus gordonii. The domain is named after the sequence found in CshA in the conserved C-terminal region. The conserved negatively charged residues suggests that this domain may bind to calcium ions. This domain is part of the non-repetitive region NR3 [1].

1: The Streptococcus gordonii Adhesin CshA Protein Binds Host Fibronectin via a Catch-Clamp Mechanism. Back CR, Sztukowska MN, Till M, Lamont RJ, Jenkinson HF, Nobbs AH, Race PR; J Biol Chem. 2017;292:1538-1549. PMID:27920201