2J2Z: X-Ray Structure Of The Chaperone Papd In Complex With The Pilus Terminator Subunit Paph At 2.3 Angstrom Resolution

Citation:
Abstract
P pili are important adhesive fibres that are assembled by the conserved chaperone-usher pathway. During pilus assembly, the subunits are incorporated into the growing fibre by the donor-strand exchange mechanism, whereby the beta-strand of the chaperone, which complements the incomplete immunoglobulin fold of each subunit, is displaced by the amino-terminal extension of an incoming subunit in a zip-in-zip-out exchange process that is initiated at the P5 pocket, an exposed hydrophobic pocket in the groove of the subunit. In vivo, termination of P pilus growth requires a specialized subunit, PapH. Here, we show that PapH is incorporated at the base of the growing pilus, where it is unable to undergo donor-strand exchange. This inability is not due to a stronger PapD-PapH interaction, but to a lack of a P5 initiator pocket in the PapH structure, suggesting that PapH terminates pilus growth because it is lacking the initiation point by which donor-strand exchange proceeds.
PDB ID: 2J2ZDownload
MMDB ID: 43036
PDB Deposition Date: 2006/8/17
Updated in MMDB: 2006/12
Experimental Method:
x-ray diffraction
Resolution: 2.3  Å
Source Organism:
Similar Structures:
Biological Unit for 2J2Z: tetrameric; determined by author and by software (PQS)
Molecular Components in 2J2Z
Label Count Molecule
Proteins (4 molecules)
2
Chaperone Protein Papd
Molecule annotation
2
PAP Fimbrial Minor Pilin Protein
Molecule annotation
Chemicals (23 molecules)
1
22
2
1
* Click molecule labels to explore molecular sequence information.

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