PROMOTER-LIKE FUNCTION OF VACCINIA VIRUS DNA FRAGMENTS IN E.COLI
Tsao Hsu Liu Genqi Zhu Jiming(Chu Chiming) (Institute of Virology, Chinese Academy of Preventive Medicine, Beijing )
During our study using β-galactosidase (Lac Z) gene as a marker for the selection of recombinant vaccinia viruses, we observed that blue bacterial colonies were formed on agar medium containing X-gal after E. coli was transfected by plasmids containing a vaccinia virus fragment with promoters for 11kd or 25kd proteins inserted upstream of the Lac Z gene.The relative level of β-galactosidase expressed by 11kd and 25kd promoters in E.coli did not run parallel to that expressed in recombinant vaccinia viruses. Lac Z gene inserted into different restriction sites of the F fragment of vaccinia virus DNA may also be expressed to different extent in E. coli,either in one orientation or in both orientations. These results showed that certain vaccinia virus DNA fragments may possess a promoter-like function in E.coli. The possible nature of this phenomenon and suggestions for further studies are discussed.