Download MendeleyModel for a Helical Bundle Channel Based on the High-Resolution Crystal Structure of Trichotoxin_A50E
Chugh, J.K., Brueckner, H., Wallace, B.A.(2002) Biochemistry 41: 12934
- PubMed: 12390019
- DOI: https://doi.org/10.1021/bi026150z
- Primary Citation of Related Structures:
1M24 - PubMed Abstract:
Trichotoxin_A50E is an 18-residue peptaibol antibiotic which forms multimeric transmembrane channels through self-association. The crystal structure of trichotoxin has been determined at a resolution of 0.9 A. The trichotoxin sequence contains nine helix-promoting Aib residues, which contribute to the formation of an entirely helical structure that has a central bend of 8-10 degrees located between residues 10-13. Trichotoxin is the first solved structure of the peptaibol family that is all alpha-helix as opposed to containing part or all 3(10)-helix. Gln residues in positions 6 and 17 produce a polar face, and are proposed to form the channel lumen. An octameric model channel has been constructed from the crystal structure. It has a central pore of approximately 4-5 A radius, a size sufficient to enable transport of ions, with a constricted region at one end, formed by a ring of Gln6 residues. Electrostatic calculations are consistent with it being a cationic channel.
Organizational Affiliation:
Department of Crystallography, Birkbeck College, University of London, London WC1E 7HX, UK.
