Download MendeleypH-triggered, activated-state conformations of the influenza hemagglutinin fusion peptide revealed by NMR.
Lorieau, J.L., Louis, J.M., Schwieters, C.D., Bax, A.(2012) Proc Natl Acad Sci U S A 109: 19994-19999
- PubMed: 23169643
- DOI: https://doi.org/10.1073/pnas.1213801109
- Primary Citation of Related Structures:
2LWA - PubMed Abstract:
The highly conserved first 23 residues of the influenza hemagglutinin HA2 subunit constitute the fusion domain, which plays a pivotal role in fusing viral and host-cell membranes. At neutral pH, this peptide adopts a tight helical hairpin wedge structure, stabilized by aliphatic hydrogen bonding and charge-dipole interactions. We demonstrate that at low pH, where the fusion process is triggered, the native peptide transiently visits activated states that are very similar to those sampled by a G8A mutant. This mutant retains a small fraction of helical hairpin conformation, in rapid equilibrium with at least two open structures. The exchange rate between the closed and open conformations of the wild-type fusion peptide is ~40 kHz, with a total open-state population of ~20%. Transitions to these activated states are likely to play a crucial role in formation of the fusion pore, an essential structure required in the final stage of membrane fusion.
Organizational Affiliation:
Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
