TlpA-like family, suppressor for copper sensitivity D protein (ScsD) and actinobacterial DsbE homolog subfamily; composed of ScsD, the DsbE homolog of Mycobacterium tuberculosis (MtbDsbE) and similar proteins, all containing a redox-active CXXC motif. The Salmonella typhimurium ScsD is a thioredoxin-like protein which confers copper tolerance to copper-sensitive mutants of E. coli. MtbDsbE has been characterized as an oxidase in vitro, catalyzing the disulfide bond formation of substrates like hirudin. The reduced form of MtbDsbE is more stable than its oxidized form, consistent with an oxidase function. This is in contrast to the function of DsbE from gram-negative bacteria which is a specific reductase of apocytochrome c.