Mutations Affecting HVO_1357 or HVO_2248 Cause Hypermotility in Haloferax volcanii, Suggesting Roles in Motility Regulation

Genes (Basel). 2020 Dec 31;12(1):58. doi: 10.3390/genes12010058.


Motility regulation plays a key role in prokaryotic responses to environmental stimuli. Here, we used a motility screen and selection to isolate hypermotile Haloferax volcanii mutants from a transposon insertion library. Whole genome sequencing revealed that hypermotile mutants were predominantly affected in two genes that encode HVO_1357 and HVO_2248. Alterations of these genes comprised not only transposon insertions but also secondary genome alterations. HVO_1357 contains a domain that was previously identified in the regulation of bacteriorhodopsin transcription, as well as other domains frequently found in two-component regulatory systems. The genes adjacent to hvo_1357 encode a sensor box histidine kinase and a response regulator, key players of a two-component regulatory system. None of the homologues of HVO_2248 have been characterized, nor does it contain any of the assigned InterPro domains. However, in a significant number of Haloferax species, the adjacent gene codes for a chemotaxis receptor/transducer. Our results provide a foundation for characterizing the root causes underlying Hfx. volcanii hypermotility.

Keywords: Haloferax volcanii; archaea; archaella; chemotaxis; extremophiles; hypermotility selection; swimming motility; transposon mutagenesis; two-component regulatory system.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Archaeal Proteins / classification
  • Archaeal Proteins / genetics*
  • Archaeal Proteins / metabolism
  • Chemotaxis / genetics*
  • Chromosome Mapping
  • Computational Biology / methods
  • DNA Transposable Elements
  • Genome, Archaeal*
  • Haloferax volcanii / genetics*
  • Haloferax volcanii / metabolism
  • Histidine Kinase / genetics
  • Histidine Kinase / metabolism
  • Mutagenesis, Insertional*
  • Mutation*
  • Whole Genome Sequencing


  • Archaeal Proteins
  • DNA Transposable Elements
  • Histidine Kinase