中国生物工程杂志

Objective: To construct pET23d-HvSRP19 expression vector for the gene of SRP19 protein of halophilic archaeon Haloferax volcanii (Hv SRP19), and induce it to express in E.coli. Then to purify and analyze the biological activity of its expressed proteins. Methods: The Hv SRP19 full length gene sequences were firstly got from a set of 10 overlapping synthetic short oligonucleotides by de novo recombinant DNA techniques and splicing, and then cloned to pET23d vector. The large expressed products of recombinant plasmid in E.coli BL21(DE3)pLysS were purified by Q-Sepharose ion exchange chromatography, and its biological activity was then analyzed by sucrose density gradient ultra-centrifugation. Results: pET23d-HvSRP19 expression vector was correctly constructed, and found to have a very good expression in E.coli. The purification of the expressed products was confirmed to be successful with an achievement of the protein pure degree up to 95%, and the purified proteins were demonstrated to have the Hv SRP19 biological activity due to it could form complex with Hv SRP RNA. Conclusions：The availability of the Hv SRP19 interaction with Hv SRP RNA was considered to be the initiation of SRP formation and performing function.