Centrioles are evolutionarily conserved cylindrical cell organelles with characteristic radial symmetry. Despite their considerable size (400 nm × 200 nm, in humans), genetic studies suggest that relatively few protein components are involved in their assembly. We recently characterized the molecular architecture of the centrosomal P4.1-associated protein (CPAP), which is crucial for controlling the centriolar cylinder length. Here, we review the remarkable architecture of the C-terminal domain of CPAP, termed the G-box, which comprises a single, entirely solvent exposed, antiparallel β-sheet. Molecular dynamics simulations support the stability of the G-box domain even in the face of truncations or amino acid substitutions. The similarity of the G-box domain to amyloids (or amyloid precursors) is strengthened by its oligomeric arrangement to form continuous fibrils. G-box fibrils were observed in crystals as well as in solution and are also supported by simulations. We conclude that the G-box domain may well represent the best analogue currently available for studies of exposed β-sheets, unencumbered by additional structural elements or severe aggregations problems.
The centriolar protein CPAP G-box: an amyloid fibril in a single domain
- Views Icon Views
- Share Icon Share
- Cite Icon Cite
Erin E. Cutts, Alison Inglis, Phillip J. Stansfeld, Ioannis Vakonakis, Georgios N. Hatzopoulos; The centriolar protein CPAP G-box: an amyloid fibril in a single domain. Biochem Soc Trans 1 October 2015; 43 (5): 838–843. doi: https://doi.org/10.1042/BST20150082
Download citation file: