This is a C-terminal domain found in BepA proteins from Bartonella henselae. It is a type IV secretion system (T4SS) effector protein. BepA from Bartonella henselae is composed of an N-terminal Fic domain and a C-terminal Bartonella intracellular delivery (ID) domain, the latter being responsible for T4SS-mediated translocation into host cells. The ID domain of BepA mediates inhibition of apoptosis and exhibits an OB (oligonucleotide/oligosaccharide binding)-fold [1].

1: Fic domain-catalyzed adenylylation: insight provided by the structural analysis of the type IV secretion system effector BepA. Palanivelu DV, Goepfert A, Meury M, Guye P, Dehio C, Schirmer T; Protein Sci. 2011;20:492-499. PMID:21213248