2W07: Structural Determinants Of Polymerization Reactivity Of The P Pilus Adaptor Subunit Papf

P pili are important adhesive fibers involved in kidney infection by uropathogenic Escherichia coli. Pilus subunits are characterized by a large groove resulting from lack of a beta strand. Polymerization of pilus subunits occurs via the donor-strand exchange (DSE) mechanism initiated when the N terminus of an incoming subunit interacts with the P5 region/pocket of the previously assembled subunit groove. Here, we solve the structure of the PapD:PapF complex in order to understand why PapF undergoes slow DSE. The structure reveals that the PapF P5 pocket is partially obstructed. MD simulations show this region of PapF is flexible compared with its equivalent in PapH, a subunit that also has an obstructed P5 pocket and is unable to undergo DSE. Using electrospray-ionization mass spectrometry, we show that mutations in the P5 region result in increased DSE rates. Thus, partial obstruction of the P5 pocket serves as a modulating mechanism of DSE.
PDB ID: 2W07Download
MMDB ID: 68091
PDB Deposition Date: 2008/8/12
Updated in MMDB: 2008/11
Experimental Method:
x-ray diffraction
Resolution: 2.2  Å
Source Organism:
Similar Structures:
Biological Unit for 2W07: dimeric; determined by author and by software (PQS)
Molecular Components in 2W07
Label Count Molecule
Proteins (2 molecules)
Chaperone Protein Papd
Molecule annotation
Minor Pilin Subunit Papf
Molecule annotation
Chemicals (2 molecules)
* Click molecule labels to explore molecular sequence information.

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