Lipid phase separation impairs membrane thickness sensing by the sensor kinase DesK.

Unlabelled: Membrane fluidity and thickness have emerged as crucial factors for the activity of and resistance to several antimicrobials. However, the lack of tools to study membrane fluidity and, in particular, thickness in living bacteria limits our understanding of this interplay. The histidine kinase/phosphatase DesK is a molecular sensor that directly detects membrane thickness.