This is a family of outer surface proteins (Osp) from the Borrelia spirochete [1]. The family includes OspE, and OspEF-related proteins (Erp) [2,3]. These proteins are coded for on different circular plasmids in the Borrelia genome.

1: Homology throughout the multiple 32-kilobase circular plasmids present in Lyme disease spirochetes. Casjens S, van Vugt R, Tilly K, Rosa PA, Stevenson B; J Bacteriol 1997;179:217-227. PMID:8982001

2: A family of genes located on four separate 32-kilobase circular plasmids in Borrelia burgdorferi B31. Stevenson B, Tilly K, Rosa PA; J Bacteriol 1996;178:3508-3516. PMID:8655548

3: Borrelia burgdorferi infection-associated surface proteins ErpP, ErpA, and ErpC bind human plasminogen. Brissette CA, Haupt K, Barthel D, Cooley AE, Bowman A, Skerka C, Wallich R, Zipfel PF, Kraiczy P, Stevenson B; Infect Immun. 2009;77:300-306. PMID:19001079