Cloning and expression of stxB gene from shigelladysenteriatypeI in E. coli Rosseta DE3

Shigellosis is a global human health problem. Currently، no vaccines against Shigella infection exist. Shiga toxin (ST) is a main virulence factor in Shigelladysenteriae type I that encoding by stx gene. This toxin is a hexameric protein with a molecular mass of 70. 5 kDa، which is composed of anStxA monomer and a receptor-binding StxBhomopentamer subunit. Shiga toxin A subunit (stxA)، mediates toxicity and B subunit (stxB) is a nontoxic proteinresponsible for toxin binding and internalization into target cells. stxB is a candidate vaccine antigen for Shigellosis. In this work، primer designing done by using of stxB gene sequence that gets from NCBI. The stxB gene was amplified by PCR than cloned in pGEM- T Easy vetorand was subcloned in pET-28a (+) as anexpression vector. stxB genewas expressed in Escherichiacoli Rosetta DE3، and purified by a Ni-NTA resin column، then detected molecular weight and immunogenicity by SDS-PAGE and Western-blot. goal of this work was production of STxB protein. Purified protein was used in our next studies such as an immunization and production of polyclonal antibody against shiga toxin.