Binds (in a non-immune fashion) to the Fc portion of human IgG but not IgA; binding occurs on the cell surface. Confers the ability to survive exposure to human serum exposure (PubMed:10722621). Binds to the Fc portion of human IgG and to whole mouse antibodies also via Fc, binds more than 1 Fc or IgG (PubMed:19303642). Homotrimer; can probably form mixed heterotrimers in vivo (PubMed:22155776). Will form mixed heterotrimers with EibD; these are correctly located in the outer membrane and bind IgG Fc, although less well than homotrimers. Does not form trimers with distantly related YadA from Y.enterocolitica; coexpression was lethal and one of the genes is eliminated in vivo. If the full translocator domain (299-392) is exchanged with that of YadA ('368-455'), will form heterotrimers with YadA and vice-versa (PubMed:22155776). In denaturing gels runs as 2 bands of about 121 and 131 kDa; extracting the sample with 88% phenol at 70 degrees Celsius reduces part of the signal to about 45 kDa (PubMed:10722621). Binds the Fc portion of IgG; binds more than 1 Fc per subunit (PubMed:19303642). The C-terminal translocator domain is localized in the outer membrane and the passenger domain is at the cell surface. In strain ECOR 9 expression is greater at 37 than 27 degrees Celsius and increases upon entry into stationary phase (at protein level). Upon expression from a plasmid in strain AB1157 (with its own leader sequence) more protein is seen at 37 than 27 degrees Celsius (at protein level). The signal peptide, cleaved at the inner membrane, guides the autotransporter protein to the periplasmic space (By similarity). Then, trimerization and insertion of the C-terminal translocator domain in the outer membrane forms a hydrophilic pore for the translocation of the passenger domain to the bacterial cell surface (PubMed:22155776). Trimerizes to make a lollipop-shaped form which consists of three domains: a C-terminal membrane-anchor domain, an extended coiled-coil stalk domain which binds IgG Fc, and an N-terminal head domain (By similarity). Encoded in an Atlas prophage region of strain ECOR 9, upon UV treatment bacteriophage containing this gene can be isolated. Belongs to the autotransporter-2 (AT-2) (TC 1.B.40) family. Eib subfamily.