This domain found at the N-terminus of the cell surface Sgo0707 protein. This domain is called the N1 domain and is involved in host colonisation.The largest domain, N1, comprises a putative binding cleft with a single cysteine located in its centre and exhibits an unexpected structural similarity to the variable domains of the streptococcal Antigen I/II adhesins [1].

1: Structural and functional analysis of the N-terminal domain of the Streptococcus gordonii adhesin Sgo0707. Nylander A, Svensater G, Senadheera DB, Cvitkovitch DG, Davies JR, Persson K; PLoS One. 2013;8:e63768. PMID:23691093