VirB8 is a bacterial virulence protein with cytoplasmic, transmembrane, and periplasmic regions. It is thought that it is a primary constituent of a DNA transporter. The periplasmic region interacts with VirB9, VirB10, and itself [1]. This family also includes the conjugal transfer protein family TrbF, a family of proteins known to be involved in conjugal transfer. The TrbF protein is thought to compose part of the pilus required for transfer [2]. This domain has a similar fold to the NTF2 protein.

1: Functional analysis of the Agrobacterium tumefaciens T-DNA transport pore protein VirB8. Kumar RB, Das A; J Bacteriol 2001;183:3636-3641. PMID:11371528

2: Biomonitoring of pJP4-carrying Pseudomonas chlororaphis with Trb protein-specific antisera. Schmidt-Eisenlohr H, Rittig M, Preithner S, Baron C; Environ Microbiol 2001;3:720-730. PMID:11846762