This family consists of several PerB or BfpV proteins found specifically in Escherichia coli. PerB is thought to play a role in regulating the expression of BfpA [1].

1: A plasmid-encoded regulatory region activates chromosomal eaeA expression in enteropathogenic Escherichia coli. Gomez-Duarte OG, Kaper JB; Infect Immun 1995;63:1767-1776. PMID:7729884

2: Cloning and characterization of bfpTVW, genes required for the transcriptional activation of bfpA in enteropathogenic Escherichia coli. Tobe T, Schoolnik GK, Sohel I, Bustamante VH, Puente JL; Mol Microbiol 1996;21:963-975. PMID:8885267