Quality control of disulfide bond formation in pilus subunits by the chaperone FimC.

摘要: Type 1 pili from uropathogenic Escherichia coli are filamentous, noncovalent protein complexes mediating bacterial adhesion to the host tissue. All structural pilus subunits homologous proteins sharing an invariant disulfide bridge. Here we show that bond formation in unfolded subunits, catalyzed by periplasmic oxidoreductase DsbA, is required for subunit recognition assembly chaperone FimC and FimC-catalyzed folding. thus guarantees quantitative each of up 3,000 pilus. The X-ray structure complex between main FimA kinetics folding indicate accelerates lowering their topological complexity. kinetic data, together with measured vivo concentrations DsbA FimC, predict half-life 2 s oxidative periplasm.