This is the N-terminal domain of the CppA protein found in species of Streptococcus. CppA is a putative C3-glycoprotein degrading proteinase, involved in pathogenicity [1,2]. It is often found associated with Pfam:PF14507.

1: Degradation of C3 by Streptococcus pneumoniae. Angel CS, Ruzek M, Hostetter MK; J Infect Dis. 1994;170:600-608. PMID:8077717

2: In silico prediction of horizontal gene transfer in Streptococcus thermophilus. Eng C, Thibessard A, Danielsen M, Rasmussen TB, Mari JF, Leblond P; Arch Microbiol. 2011;193:287-297. PMID:21234750