A1 Vertaisarvioitu alkuperäisartikkeli tieteellisessä lehdessä
Allosteric Mechanism Controls Traffic in the Chaperone/Usher Pathway
Tekijät: Di Yu X, Dubnovitsky A, Pudney AF, MacIntyre S, Knight SD, Zavialov AV
Kustantaja: CELL PRESS
Julkaisuvuosi: 2012
Journal: Structure
Tietokannassa oleva lehden nimi: STRUCTURE
Lehden akronyymi: STRUCTURE
Numero sarjassa: 11
Vuosikerta: 20
Numero: 11
Aloitussivu: 1861
Lopetussivu: 1871
Sivujen määrä: 11
ISSN: 0969-2126
DOI: https://doi.org/10.1016/j.str.2012.08.016
Tiivistelmä
Many virulence organelles of Gram-negative bacterial pathogens are assembled via the chaperone/usher pathway. The chaperone transports organelle subunits across the periplasm to the outer membrane usher, where they are released and incorporated into growing fibers. Here, we elucidate the mechanism of the usher-targeting step in assembly of the Yersinia pestis F1 capsule at the atomic level. The usher interacts almost exclusively with the chaperone in the chaperone:subunit complex. In free chaperone, a pair of conserved proline residues at the beginning of the subunit-binding loop form a "proline lock" that occludes the usher-binding surface and blocks usher binding. Binding of the subunit to the chaperone rotates the proline lock away from the usher-binding surface, allowing the chaperone-subunit complex to bind to the usher. We show that the proline lock exists in other chaperone/usher systems and represents a general allosteric mechanism for selective targeting of chaperone:subunit complexes to the usher and for release and recycling of the free chaperone.
Many virulence organelles of Gram-negative bacterial pathogens are assembled via the chaperone/usher pathway. The chaperone transports organelle subunits across the periplasm to the outer membrane usher, where they are released and incorporated into growing fibers. Here, we elucidate the mechanism of the usher-targeting step in assembly of the Yersinia pestis F1 capsule at the atomic level. The usher interacts almost exclusively with the chaperone in the chaperone:subunit complex. In free chaperone, a pair of conserved proline residues at the beginning of the subunit-binding loop form a "proline lock" that occludes the usher-binding surface and blocks usher binding. Binding of the subunit to the chaperone rotates the proline lock away from the usher-binding surface, allowing the chaperone-subunit complex to bind to the usher. We show that the proline lock exists in other chaperone/usher systems and represents a general allosteric mechanism for selective targeting of chaperone:subunit complexes to the usher and for release and recycling of the free chaperone.
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