Objective To clone the recombinant fusion gene ofEscherichia coliheat-liable enterotoxin B subunit (Ltb) and Actinobacillus actinomycetemcomitansfimbria associative protein (Fap).Methods Two couples of primerswere designed for PCR according to the known sequence of ltb and fap. The ltb and fap gene were obtained by amplification PCR technique from plasmid EWD299 ofEscherichia coliandActinobacillus actinomycetemcomitans310 DNArespectively, and fused them by PCR. The fusion gene ltb-fap were cloning into plasmid pET28a(+). The recombined plasmid pET28a ltb-fapwas transformed intoEscherichia coli DH5α. The recombinant was screened and identified by restriction enzyme and PCR. The cloned gene was sequenced.Results The ltb-fap about 531bp in sizewas obtained successfully , and identified by PCR, restrictive enzyme and sequence analysis.Con- clusion The vector of pET28a ltb-fap was obstained.
