Interaction of two strongly divergent archaellins stabilizes the structure of the Halorubrum archaellum

The significance of archaellin multiplicity remains unclear. We compared two Halorubrum lacusprofundi strains, one of them has two extraordinarily diverged archaellin genes, while another one has only one gene. In addition we engineered Haloferax volcanii strains synthesizing recombinant archaella of Hrr. lacusprofundi archaellins. The results suggest that functional supercoiled archaella can be composed from only one archaellin. However, interaction of two different archaellins provides additional stabilization to the archaellum structure and thus adaptation to a wider range of environments. AbstractHalophilic archaea from the genusHalorubrum possess two extraordinarily diverged archaellin genes,flaB1 andflaB2. To clarify roles for each archaellin, we compared two naturalHalorubrum lacusprofundi strains: One of them contains both archaellin genes, and the other has theflaB2 gene only. Both strains synthesize functional archaella; however, the strain, where both archaellins are present, is more motile. In addition, we expressed these archaellins in aHaloferax volcanii strain from which the endogenous archaellin genes were deleted. ThreeHfx. volcanii strains expressingHrr. lacusprofundi archaellins produced functional filaments consisting of only one (FlaB1 or FlaB2) or both (FlaB1/FlaB2) archaellins. All three strains were motile, although there were profound differences in the efficiency of motility. Both native and recombinant FlaB1/FlaB2 filaments have greater thermal stab...
Source: MicrobiologyOpen - Category: Microbiology Authors: Tags: ORIGINAL ARTICLE Source Type: research