Cloning and Expression of Variable Domain (V+) Gene of Surface Protein of Streptococcus Mutans

ObjectiveTo isolate variable domain(V+)gene of the surface protein of streptococcus mutans and construct an expressive clone of V+gene.MethodsV+do main was amplified from gene sr by poly merase chain reaction(PCR)and subcloned into the plasmid vector pCR2.1 and the expressive plasmid vector pET21a(+).The recombinant was induced by IPTG to express target protein which was analysed by SDS-PAGE Western blotting.ResultsThe specific product of PCR was about 1.16bp which was subcloned into vectors.The recombinant clone pCVf and the recombinant expressive clone pSRVf were obtained.pSRVf expressed specific protein with a molecular weight of 43kDa.This recombinant protein could be specifically recog nized by anti Ⅰ/Ⅱ serum.ConclusionV+domain of sr gene was cloned successfully.