[Plasmid DNA fragments from Halobacterium halobium active as eubacteria promoters in Escherichia coli]

In this paper; a promoter-probe plasmid pKK232-8 was used as a vector which functioned in E. coli. The plasmid pHH205 of Halobacterium halobium J7 was digested by two groups of restriction endonucleases BamHI-SalI and HindIII -SalI, recombined in vitro and transformed into E. coli. The transformants were selected on resistance plates to contain ampicillin (Am) and chloramphenicol (Cm). From random-selected 20 strains of transformants we obtained transformants T1 and T2, whose level of Cm resistance got to 110 micrograms/ml. The recombinant plasmids from T1 and T2 were named pJH and pJB, respectively. The resultes of analysis by restriction endonucleases digestion and molecular hybridization showed that recombinant plasmid pJH carried a inserted fragment with size of 800bp from plasmid pHH205. Experimental results of retransfomation proved further that the DNA fragment had promoter function in E. coli. Thus, this indicated that DNA fragments from plasmid of archaebaeteria (H halobium) may function as eubacteria (E. coil) promoters.