Studies On Halorhodopsin Encoding Gene And Phylogeny Of Halophilic Archaea AB19, AB30 And AJ5

Halophilic archaea belonging to the order Halobacteriales have been isolated from various hypersaline environments such as the Dead Sea, the Great Salt Lake, and natural or artificial salterns. Halorhodopsin (HR) is a retinal-binding membrane protein with seven membrane-spanning segments and functions as a light-driven anion pump in halophilic archaea. As a simple membrane protein, HR possesses great research values. In this dissertation, we reviewed the development of molecular phylogenetic taxonomy, the study on the structure and function of HR protein, and gene evolution of the archaeon rhodopsin famliay (ARF). Our research focused on the molecular phylogenetic taxonomy of the halobacterial strains from Xinjiang Region, the analysis on hop gene fragment, and the gene evolution of bop and hop.The hop partial sequences enoding for helix C to G of HR in strains AB19, AB30 and AJ5 were obtained. The 16S rDNA sequence and partial bop gene sequence of AB19 were amplified by PCR, and their DNA sequences were determined. The results indicated that compared the deduced amino acid sequence with other existent HRs, HR proteins from AB19, AB30 and AJ5 is visibly different to others. The homology analysis about HR gene, BR gene and 16S rDNA as well as phylognetic analysis about 16S rDNA showed that the strains AB19 and AB30 are new members of the genus Haloarcula and Haloterrigena, respectively. The detectation of AJ5 HR is the first in the genus Halobiforma. The GenBank accession number of the 16S rDNA sequence, hop and bop of strain AB19 is DQ471854, DQ471855 and DQ352132, respectively.