A functional promoter from the archaeon Halobacterium salinarum is also transcriptionally active in E. coli

Archaea form a third domain of life that is distinct from Bacteria and Eukarya. So far, many scholars have elucidated considerable details about the typical promoter architectures of the three domains of life. However, a functional promoter from the archaeon Halobacterium salinarum has never been studied in Escherichia coli.

This paper found that the promoter of Halobacterium salinarum showed a promoter function in Escherichia coli. This Escherichia coli promoter structure contains - 10 box, -10 box extension and - 29 elements, however, no -35 box. The - 29 element is exercised by the TATA box in archaea. And we isolated the RM10 fragment that possessed the fusion characteristics of bacteria and archaea, which was overlapped with functionality of TATA box and - 29 elements.

The - 29 element reflects the evolutionary relationship between the archaeal promoter and the bacterial promoter. The result possibly indicated that there may be a certain internal connection between archaea and bacteria. We hypothesized that it provided a new viewpoint of the evolutionary relationship of archaea and other organisms.