The Vibrio vulnificus stressosome is an oxygen-sensor involved in regulating iron metabolism

Commun Biol. 2022 Jun 27;5(1):622. doi: 10.1038/s42003-022-03548-w.


Stressosomes are stress-sensing protein complexes widely conserved among bacteria. Although a role in the regulation of the general stress response is well documented in Gram-positive bacteria, the activating signals are still unclear, and little is known about the physiological function of stressosomes in the Gram-negative bacteria. Here we investigated the stressosome of the Gram-negative marine pathogen Vibrio vulnificus. We demonstrate that it senses oxygen and identified its role in modulating iron-metabolism. We determined a cryo-electron microscopy structure of the VvRsbR:VvRsbS stressosome complex, the first solved from a Gram-negative bacterium. The structure points to a variation in the VvRsbR and VvRsbS stoichiometry and a symmetry breach in the oxygen sensing domain of VvRsbR, suggesting how signal-sensing elicits a stress response. The findings provide a link between ligand-dependent signaling and an output - regulation of iron metabolism - for a stressosome complex.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Proteins / metabolism
  • Cryoelectron Microscopy
  • Gene Expression Regulation, Bacterial
  • Iron / metabolism
  • Oxygen / metabolism
  • Vibrio vulnificus* / genetics
  • Vibrio vulnificus* / metabolism


  • Bacterial Proteins
  • Iron
  • Oxygen