Brucella Periplasmic Protein EipB Is a Molecular Determinant of Cell Envelope Integrity and Virulence

Abstract

Brucella species cause brucellosis, a global zoonosis. A gene encoding a conserved DUF1849-family protein, which we have named EipB, is present in all sequenced Brucella and several other genera in the class Alphaproteobacteria . The manuscript provides the first functional and structural characterization of a DUF1849 protein. We show that EipB is secreted to the periplasm where it forms a spiral-shaped antiparallel β protein that is a determinant of cell envelope integrity in vitro and virulence in an animal model of disease. eipB genetically interacts with ttpA , which also encodes a periplasmic protein. We propose that EipB and TtpA function as part of a system required for cell envelope homeostasis in select Alphaproteobacteria .