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Title | Structural similarity of secretins from type II and type III secretion systems. |
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Journal, issue, pages | Structure, Vol. 22, Issue 9, Page 1348-1355, Year 2014 |
Publish date | Sep 2, 2014 |
Authors | Tommaso Tosi / Leandro F Estrozi / Viviana Job / Ingrid Guilvout / Anthony P Pugsley / Guy Schoehn / Andréa Dessen / |
PubMed Abstract | Secretins, the outer membrane components of several secretion systems in Gram-negative bacteria, assemble into channels that allow exoproteins to traverse the membrane. The membrane-inserted, ...Secretins, the outer membrane components of several secretion systems in Gram-negative bacteria, assemble into channels that allow exoproteins to traverse the membrane. The membrane-inserted, multimeric regions of PscC, the Pseudomonas aeruginosa type III secretion system secretin, and PulD, the Klebsiella oxytoca type II secretion system secretin, were purified after cell-free synthesis and their structures analyzed by single particle cryoelectron microscopy. Both homomultimeric, barrel-like structures display a "cup and saucer" architecture. The "saucer" region of both secretins is composed of two distinct rings, with that of PulD being less segmented than that of PscC. Both secretins have a central chamber that is occluded by a plug linked to the chamber walls through hairpin-like structures. Comparisons with published structures from other bacterial systems reveal that secretins have regions of local structural flexibility, probably reflecting their evolved functions in protein secretion and needle assembly. |
External links | Structure / PubMed:25156426 |
Methods | EM (single particle) |
Resolution | 8.2 - 14.4 Å |
Structure data | EMDB-2628: EMDB-2629: |
Source |
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