5D6H: Crystal Structure Of Csuc-csua/b Chaperone-major Subunit Pre-assembly Complex From Csu Biofilm-mediating Pili Of Acinetobacter Baumannii

Citation:
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.
PDB ID: 5D6HDownload
MMDB ID: 133943
PDB Deposition Date: 2015/8/12
Updated in MMDB: 2015/12
Experimental Method:
x-ray diffraction
Resolution: 2.4  Å
Source Organism:
Similar Structures:
Biological Unit for 5D6H: dimeric; determined by author and by software (PISA)
Molecular Components in 5D6H
Label Count Molecule
Proteins (2 molecules)
1
Csuc
Molecule annotation
1
Csua/b
Molecule annotation
* Click molecule labels to explore molecular sequence information.

Citing MMDB
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