4AV2

Single particle electron microscopy of PilQ dodecameric complexes from Neisseria meningitidis.

Summary for 4AV2

• Entry DOI: 10.2210/pdb4av2/pdb
• Related: 2IVW 4AQZ 4AR0
• EMDB information: 2105
• Descriptor: TYPE IV PILUS BIOGENESIS AND COMPETENCE PROTEIN PILQ, PILP PROTEIN (2 entities in total)
• Functional Keywords: protein transport, outer membrane protein, pilus biogenesis
• Biological source: NEISSERIA MENINGITIDIS MC58; More
• Total number of polymer chains: 24
• Total formula weight: 1202609.04

Authors

Berry, J.L.,Phelan, M.M.,Collins, R.F.,Adomavicius, T.,Tonjum, T.,Frye, S.A.,Bird, L.,Owens, R.,Ford, R.C.,Lian, L.Y.,Derrick, J.P. (deposition date: 2012-05-23, release date: 2012-10-17, Last modification date: 2024-05-08)

Primary citation

Berry, J.L.,Phelan, M.M.,Collins, R.F.,Adomavicius, T.,Tonjum, T.,Frye, S.A.,Bird, L.,Owens, R.,Ford, R.C.,Lian, L.Y.,Derrick, J.P.
Structure and Assembly of a Trans-Periplasmic Channel for Type Iv Pili in Neisseria Meningitidis.
Plos Pathog., 8:2923-, 2012

PubMed Abstract: Type IV pili are polymeric fibers which protrude from the cell surface and play a critical role in adhesion and invasion by pathogenic bacteria. The secretion of pili across the periplasm and outer membrane is mediated by a specialized secretin protein, PilQ, but the way in which this large channel is formed is unknown. Using NMR, we derived the structures of the periplasmic domains from N. meningitidis PilQ: the N-terminus is shown to consist of two β-domains, which are unique to the type IV pilus-dependent secretins. The structure of the second β-domain revealed an eight-stranded β-sandwich structure which is a novel variant of the HSP20-like fold. The central part of PilQ consists of two α/β fold domains: the structure of the first of these is similar to domains from other secretins, but with an additional α-helix which links it to the second α/β domain. We also determined the structure of the entire PilQ dodecamer by cryoelectron microscopy: it forms a cage-like structure, enclosing a cavity which is approximately 55 Å in internal diameter at its largest extent. Specific regions were identified in the density map which corresponded to the individual PilQ domains: this allowed us to dock them into the cryoelectron microscopy density map, and hence reconstruct the entire PilQ assembly which spans the periplasm. We also show that the C-terminal domain from the lipoprotein PilP, which is essential for pilus assembly, binds specifically to the first α/β domain in PilQ and use NMR chemical shift mapping to generate a model for the PilP:PilQ complex. We conclude that passage of the pilus fiber requires disassembly of both the membrane-spanning and the β-domain regions in PilQ, and that PilP plays an important role in stabilising the PilQ assembly during secretion, through its anchorage in the inner membrane.

PubMed: 23028322
DOI: 10.1371/JOURNAL.PPAT.1002923

Experimental method

ELECTRON MICROSCOPY (26 Å)