2CO6

Salmonella enterica SafA pilin in complex with the SafB chaperone (Type I)

Summary for 2CO6

• Entry DOI: 10.2210/pdb2co6/pdb
• Related: 2CNY 2CNZ 2CO1 2CO2 2CO3 2CO4 2CO7
• Descriptor: PUTATIVE OUTER MEMBRANE PROTEIN, PUTATIVE FIMBRIAE ASSEMBLY CHAPERONE (3 entities in total)
• Functional Keywords: pilus subunit, adhesion, strand complementation, pathogenesis, chaperone, fibril protein
• Biological source: SALMONELLA TYPHIMURIUM; More
• Cellular location: Periplasm (By similarity): Q8ZRK3
• Total number of polymer chains: 2
• Total formula weight: 37159.95

Authors

Remaut, H.,Rose, R.J.,Hannan, T.J.,Hultgren, S.J.,Radford, S.E.,Ashcroft, A.E.,Waksman, G. (deposition date: 2006-05-25, release date: 2006-06-27, Last modification date: 2024-10-09)

Primary citation

Remaut, H.,Rose, R.J.,Hannan, T.J.,Hultgren, S.J.,Radford, S.E.,Ashcroft, A.E.,Waksman, G.
Donor-Strand Exchange in Chaperone-Assisted Pilus Assembly Proceeds Through a Concerted Beta-Strand Displacement Mechanism
Mol.Cell, 22:831-, 2006

PubMed Abstract: Gram-negative pathogens commonly use the chaperone-usher pathway to assemble adhesive multisubunit fibers on their surface. In the periplasm, subunits are stabilized by a chaperone that donates a beta strand to complement the subunits' truncated immunoglobulin-like fold. Pilus assembly proceeds through a "donor-strand exchange" (DSE) mechanism whereby this complementary beta strand is replaced by the N-terminal extension (Nte) of an incoming pilus subunit. Using X-ray crystallography and real-time electrospray ionization mass spectrometry (ESI-MS), we demonstrate that DSE requires the formation of a transient ternary complex between the chaperone-subunit complex and the Nte of the next subunit to be assembled. The process is crucially dependent on an initiation site (the P5 pocket) needed to recruit the incoming Nte. The data also suggest a capping reaction displacing DSE toward product formation. These results support a zip-in-zip-out mechanism for DSE and a catalytic role for the usher, the molecular platform at which pili are assembled.

PubMed: 16793551
DOI: 10.1016/J.MOLCEL.2006.05.033

Experimental method

X-RAY DIFFRACTION (2 Å)