coding site
3.Methods The recombinant adenovirus coding for human SSTR2(Ad-SSTR2)and reporter gene LacZ(Ad-LacZ)were generated by site-specific recombination from Jun 1,2004 to Dec 10,2005.Human pancreatic cancer cell line was implanted subcutaneously into nude mice;
4.Formate dehydrogenase(FDH)coding gene was amplified from genomic DNA of Pichia pastoris by polymerase chain reaction, and the codon TAG(bases 649-651)was mutated to GAG using site-directed mutagenesis. The recombinant plasmid pET-FDH was con- structed by inserting the mutated DNA fragment into expression vector pET-22b(+),and transformed into E. coli BL21(DE3).
7.The Hybrid antigen gene SA-28 coding for a modified Hepatitis B surface antigen and preS1 epitope was ligated with a synthetic adaptor and placed at down stream of a hybrid promoter ADH2-SUC2. The expression cassatte was then inserted into BamHI site of highly stable plasmid pHC11 to construct expression vectors, YFD150 and YFD150-o. After transforming them into yeast Y19, the expression of SA-28 gene was studied.
8.In order to study structure and function of Escherichia coli arginyl tRNA synthetase (ArgRS), deletion of R245 and 252 in this enzyme was carried out by site directed mutagenesis of gene coding for this enzyme, respectively. The genes, argSΔr 245 and argSΔr 252 encoding ArgRS mutant, ArgRSΔR245 and ArgRSΔR252 were obtained and cloned into pUC18 or pTrc99B, respectively.
9.The main work in this task is the construction of integration expression vectors Pyzq-3, the vector Pyzq-3 is base on the vector PAX01 bone, assembled from the promoter PA glvA which derived from the glv operon of Bacillus subtilis and exist a site mutation in catabolite repression element , and from the report gene ,the bgaB gene, coding for heat-stable P -Gal which derived from the Bacillus stearothermophilus.
