DELETION ANALYSIS OF DNA FRAGMENT RM07 FROM HALOBACTERIUM HALOBIUM / 微生物学通报

ABSTRACT

The DNA fragment RM07 was isolated from halophilic archaea Halobacterium halobium, which can function as promoter not only in halophilic archaea, but also in Escherichia coli as eubacterial promoter. Sequencing analysis indicated that it possessed the typical consensus sequences (-35 and -10) of bacterial gene promoter, which was confirmed by further deletion analysis: With its -35 sequence deleted and -10 sequence left,DNA fragment RM07a nearly cannot initiate transcription;With its both -35 and -10 sequences,RM07b DNA fragment could be active as promoter at a level even higher than RM07. Our research also showed that the promoter function of RM07 fragment in Escherichia coli was under the control of environmental factors,especially its positive correlation with the increasing concentration of sodium chloride. Therefore, RM07 DNA fragment may be potential1 novel promoter source for constructing double-function vectors. It also has special significance in elucidating the issues of the fusing characteristics of archaea and lateral gene transfer between archaea and bacteria.