5D6H

Crystal structure of CsuC-CsuA/B chaperone-major subunit pre-assembly complex from Csu biofilm-mediating pili of Acinetobacter baumannii

Summary for 5D6H

• Entry DOI: 10.2210/pdb5d6h/pdb
• Descriptor: CsuC, CsuA/B (3 entities in total)
• Functional Keywords: archaic chaperone-usher pathway, ig-like fold, beta sheet sandwich, donor-strand complementation, chaperone-protein transport complex, chaperone/protein transport
• Biological source: Acinetobacter baumannii; More
• Total number of polymer chains: 2
• Total formula weight: 43122.66

Authors

Pakharukova, N.A.,Tuitilla, M.,Paavilainen, S.,Zavialov, A. (deposition date: 2015-08-12, release date: 2015-11-04, Last modification date: 2024-11-13)

Primary citation

Pakharukova, N.,Garnett, J.A.,Tuittila, M.,Paavilainen, S.,Diallo, M.,Xu, Y.,Matthews, S.J.,Zavialov, A.V.
Structural Insight into Archaic and Alternative Chaperone-Usher Pathways Reveals a Novel Mechanism of Pilus Biogenesis.
Plos Pathog., 11:e1005269-e1005269, 2015

PubMed Abstract: Gram-negative pathogens express fibrous adhesive organelles that mediate targeting to sites of infection. The major class of these organelles is assembled via the classical, alternative and archaic chaperone-usher pathways. Although non-classical systems share a wider phylogenetic distribution and are associated with a range of diseases, little is known about their assembly mechanisms. Here we report atomic-resolution insight into the structure and biogenesis of Acinetobacter baumannii Csu and Escherichia coli ECP biofilm-mediating pili. We show that the two non-classical systems are structurally related, but their assembly mechanism is strikingly different from the classical assembly pathway. Non-classical chaperones, unlike their classical counterparts, maintain subunits in a substantially disordered conformational state, akin to a molten globule. This is achieved by a unique binding mechanism involving the register-shifted donor strand complementation and a different subunit carboxylate anchor. The subunit lacks the classical pre-folded initiation site for donor strand exchange, suggesting that recognition of its exposed hydrophobic core starts the assembly process and provides fresh inspiration for the design of inhibitors targeting chaperone-usher systems.

PubMed: 26587649
DOI: 10.1371/journal.ppat.1005269

Experimental method

X-RAY DIFFRACTION (2.4 Å)