This family consists of several bacterial VirJ virulence proteins. VirJ is thought to be involved in the type IV secretion system. It is thought that the substrate proteins localised to the periplasm may associate with the pilus in a manner that is mediated by VirJ, and suggest a two-step process for type IV secretion in Agrobacterium [1].

1: Agrobacterium type IV secretion is a two-step process in which export substrates associate with the virulence protein VirJ in the periplasm. Pantoja M, Chen L, Chen Y, Nester EW; Mol Microbiol 2002;45:1325-1335. PMID:12207700