The periplasmic chaperone SurA plays a key role in outer membrane protein (OMP) biogenesis. E. coli SurA comprises a core domain and two peptidylprolyl isomerase domains (P1 and P2), but its mechanisms of client binding and chaperone function have remained unclear. Here, we use chemical cross-linking, hydrogen-deuterium exchange mass spectrometry, single-molecule FRET and molecular dynamics simulations to map the client binding site(s) on SurA and interrogate the role of conformational dynamics in OMP recognition. We demonstrate that SurA samples an array of conformations in solution in which P2 primarily lies closer to the core/P1 domains than suggested in the SurA crystal structure. OMP binding sites are located primarily in the core domain, and OMP binding results in conformational changes between the core/P1 domains. Together, the results suggest that unfolded OMP substrates bind in a cradle formed between the SurA domains, with structural flexibility between domains assisting OMP recognition, binding and release.

• MeSH
• Escherichia coli metabolismus   MeSH
• hmotnostní spektrometrie MeSH
• molekulární chaperony genetika   metabolismus   MeSH
• peptidylprolylisomerasa genetika   metabolismus   MeSH
• proteiny vnější bakteriální membrány genetika   metabolismus   MeSH
• proteiny z Escherichia coli genetika   metabolismus   MeSH
• transportní proteiny genetika   metabolismus   MeSH
• vazba proteinů MeSH
• vazebná místa MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• molekulární chaperony MeSH
• peptidylprolylisomerasa MeSH
• proteiny vnější bakteriální membrány MeSH
• proteiny z Escherichia coli MeSH
• SurA protein, E coli MeSH Prohlížeč
• transportní proteiny MeSH