Download MendeleyCryo-EM structure of lysenin pore elucidates membrane insertion by an aerolysin family protein
Bokori-Brown, M., Martin, T.G., Naylor, C.E., Basak, A.K., Titball, R.W., Savva, C.G.(2016) Nat Commun 7: 11293-11293
- PubMed: 27048994
- DOI: https://doi.org/10.1038/ncomms11293
- Primary Citation of Related Structures:
5GAQ - PubMed Abstract:
Lysenin from the coelomic fluid of the earthworm Eisenia fetida belongs to the aerolysin family of small β-pore-forming toxins (β-PFTs), some members of which are pathogenic to humans and animals. Despite efforts, a high-resolution structure of a channel for this family of proteins has been elusive and therefore the mechanism of activation and membrane insertion remains unclear. Here we determine the pore structure of lysenin by single particle cryo-EM, to 3.1 Å resolution. The nonameric assembly reveals a long β-barrel channel spanning the length of the complex that, unexpectedly, includes the two pre-insertion strands flanking the hypothetical membrane-insertion loop. Examination of other members of the aerolysin family reveals high structural preservation in this region, indicating that the membrane-insertion pathway in this family is conserved. For some toxins, proteolytic activation and pro-peptide removal will facilitate unfolding of the pre-insertion strands, allowing them to form the β-barrel of the channel.
Organizational Affiliation:
Biosciences, College of Life and Environmental Sciences, University of Exeter, Stocker Road, Exeter EX4 4QD, UK.
