Calcium-Controlled Conformational Choreography in the N-Terminal Half of Adseverin.Chumnarnsilpa, S., Robinson, R.C., Grimes, J.M., Leyrat, C.
(2015) Nat.Commun. 6: 8254
- PubMed: 26365202
- DOI: 10.1038/ncomms9254
- Primary Citation of Related Structures:
- PubMed Abstract:
Adseverin is a member of the calcium-regulated gelsolin superfamily of actin-binding proteins. Here we report the crystal structure of the calcium-free N-terminal half of adseverin (iA1-A3) and the Ca(2+)-bound structure of A3, which reveal structura ...
Adseverin is a member of the calcium-regulated gelsolin superfamily of actin-binding proteins. Here we report the crystal structure of the calcium-free N-terminal half of adseverin (iA1-A3) and the Ca(2+)-bound structure of A3, which reveal structural similarities and differences with gelsolin. Solution small-angle X-ray scattering combined with ensemble optimization revealed a dynamic Ca(2+)-dependent equilibrium between inactive, intermediate and active conformations. Increasing calcium concentrations progressively shift this equilibrium from a main population of inactive conformation to the active form. Molecular dynamics simulations of iA1-A3 provided insights into Ca(2+)-induced destabilization, implicating a critical role for the A2 type II calcium-binding site and the A2A3 linker in the activation process. Finally, mutations that disrupt the A1/A3 interface increase Ca(2+)-independent F-actin severing by A1-A3, albeit at a lower efficiency than observed for gelsolin domains G1-G3. Together, these data address the calcium dependency of A1-A3 activity in relation to the calcium-independent activity of G1-G3.
Institute of Molecular and Cell Biology, A*STAR (Agency for Science, Technology and Research), Biopolis, Singapore 138673, Singapore.,Department of Biochemistry, National University of Singapore, 8 Medical Drive, Singapore 117597, Singapore.,Science Division, Diamond Light Source Ltd, Diamond House, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, UK.,Division of Structural Biology, University of Oxford, Henry Wellcome Building for Genomic Medicine, Oxford OX3 7BN, UK.,School of Biochemistry, Institute of Science, Suranaree University of Technology, 111 University Avenue, Muang, Nakhon Ratchasima 30000, Thailand.