Topology of the outer membrane usher PapC determined by site-directed fluorescence labeling.

The usher N terminus is the initial targeting site for chaperone-subunit complexes and participates in subsequent pilus biogenesis events.

Pilus biogenesis on the surface of uropathogenic Escherichia coli requires the chaperone/usher pathway, a terminal branch of the general secretory pathway. In this pathway, periplasmic chaperone-subunit complexes target an outer membrane (OM) usher for subunit assembly into pili and secretion to the cell surface. The molecular mechanisms of protein secretion across the OM are not well understoo...

Bacterial outer membrane ushers contain distinct targeting and assembly domains for pilus biogenesis.

Biogenesis of a superfamily of surface structures by gram-negative bacteria requires the chaperone/usher pathway, a terminal branch of the general secretory pathway. In this pathway a periplasmic chaperone works together with an outer membrane usher to direct substrate folding, assembly, and secretion to the cell surface. We analyzed the structure and function of the PapC usher required for P p...

Figures and figure supplements Allosteric signalling in the outer membrane translocation domain of PapC usher Irene

Chaperone-assisted self-assembly of pili independent of cellular energy.

Assembly of P pili on the surface of pyelonephritic Escherichia coli proceeds from periplasmic chaperone-subunit complexes. The outer membrane protein PapC, which has been termed a molecular usher, is thought to be the site of assembly, where the chaperone dissociates from the subunits as they are incorporated into the pilus across the outer membrane. The kinetics of assembly and the energy req...

Structural homology between the C-terminal domain of the PapC usher and its plug.

P pili are extracellular appendages responsible for the targeting of uropathogenic Escherichia coli to the kidney. They are assembled by the chaperone-usher (CU) pathway of pilus biogenesis involving two proteins, the periplasmic chaperone PapD and the outer membrane assembly platform, PapC. Many aspects of the structural biology of the Pap CU pathway have been elucidated, except for the C-term...