biostudies-literatureUnknown119(9)Chamachi NPeriplasmic chaperones 17-kilodalton protein (Skp) and survival factor A (SurA) are essential players in outer membrane protein (OMP) biogenesis. They prevent unfolded OMPs from misfolding during their passage through the periplasmic space and aid in the disassembly of OMP aggregates under cellular stress conditions. However, functionally important links between interaction mechanisms, structural dynamics, and energetics that underpin both Skp and SurA associations with OMPs have remained largely unresolved. Here, using single-molecule fluorescence spectroscopy, we dissect the conformational dynamics and thermodynamics of Skp and SurA binding to unfolded OmpX and explore their disaggregase activities. We show that both chaperones expand unfolded OmpX distinctly and induce microsecond chainProceedings of the National Academy of Sciences of the United States of Americae2118919119https://www.ebi.ac.uk/biostudies/studies/S-EPMC8892499biostudies-literatureChaperones Skp and SurA dynamically expand unfolded OmpX and synergistically disassemble oligomeric aggregates.PMC8892499Schlierf MHartmann AMa MQChamachi NKrainer GSvirina AfalseChaperones Skp and SurA dynamically expand unfolded OmpX and synergistically disassemble oligomeric aggregates.Periplasmic chaperones 17-kilodalton protein (Skp) and survival factor A (SurA) are essential players in outer membrane protein (OMP) biogenesis. They prevent unfolded OMPs from misfolding during their passage through the periplasmic space and aid in the disassembly of OMP aggregates under cellular stress conditions. However, functionally important links between interaction mechanisms, structural dynamics, and energetics that underpin both Skp and SurA associations with OMPs have remained largely unresolved. Here, using single-molecule fluorescence spectroscopy, we dissect the conformational dynamics and thermodynamics of Skp and SurA binding to unfolded OmpX and explore their disaggregase activities. We show that both chaperones expand unfolded OmpX distinctly and induce microsecond chain2022-01-01T00:00:00Z2022 Mar2025-04-22T22:04:44.275Z2025-04-06T03:54:19.075ZS-EPMC88924993521761910.1073/pnas.2118919119