1yp8
From Proteopedia
Solution structure of the cyclotide tricyclon A
Overview
Cyclotides are a family of plant proteins that have the unusual combination of head-to-tail backbone cyclization and a cystine knot motif. They are exceptionally stable and show resistance to most chemical, physical, and enzymatic treatments. The structure of tricyclon A, a previously unreported cyclotide, is described here. In this structure, a loop that is disordered in other cyclotides forms a beta sheet that protrudes from the globular core. This study indicates that the cyclotide fold is amenable to the introduction of a range of structural elements without affecting the cystine knot core of the protein, which is essential for the stability of the cyclotides. Tricyclon A does not possess a hydrophobic patch, typical of other cyclotides, and has minimal hemolytic activity, making it suitable for pharmaceutical applications. The 22 kDa precursor protein of tricyclon A was identified and provides clues to the processing of these fascinating miniproteins.
About this Structure
Full crystallographic information is available from OCA.
Reference
Processing of a 22 kDa precursor protein to produce the circular protein tricyclon A., Mulvenna JP, Sando L, Craik DJ, Structure. 2005 May;13(5):691-701. PMID:15893660 Page seeded by OCA on Sat May 3 16:36:37 2008
