Protein Domain : DsbB-like superfamily IPR023380

Type	Homologous_superfamily
Description	Disulphide bonds contribute to folding, maturation, stability, and regulation of proteins, in particular those localized out of the cytosol. Oxidation of selected pairs of cysteines to disulphide in vivo requires cellular factors present in the bacterial periplasmic space or in the endoplasmic reticulum of eukaryotic cells [, ].The disulfide bond formation protein B (DsbB) is a component of the pathway that leads to disulphide bond formation in periplasmic proteins of Escherichia coli and other bacteria. The DsbB protein oxidises the periplasmic protein DsbA which in turn oxidises cysteines in other periplasmic proteins in order to make disulphide bonds [ ]. DsbB acts as a redox potential transducer across the cytoplasmic membrane. It is a membrane protein which spans the membrane four times with both the N- and C-termini of the protein are in the cytoplasm. Each of the periplasmic domains of the protein has two essential cysteines. The two cysteines in the first periplasmic domain are in a Cys-X-Y-Cys configuration that is characteristic of the active site of other proteins involved in disulphide bond formation, including DsbA and protein disulphide isomerase [].The structure of DsbB contains four transmembrane (TM) helices with both termini oriented toward the cytoplasm. The four TM segments are arranged into a four-helix-bundle configuration. In addition to these TM helices, a short helix with a horizontal axis exists in the periplasmic region [ ].
Short Name	DsbB-like_sf