Forum 12/07/2006

“The chaperonin machine and its interactions with non-native proteins”

Helen Saibil, Ph.D. – Department of Crystallography, Birkbeck College London

This talk will be on cryo EM and single particle analysis of chaperonin (GroEL-GroES) complexes, focusing on their ATP-coordinated switching between binding, encapsulation and release states for folding substrate proteins, and on the distribution of substrate protein density in the binding cavities. Domain rotations between the different allosteric states of GroEL cause dramatic changes in the accessibility of hydrophobic binding surfaces. Analysis and sorting of heterogeneous mixtures of folding states bound on the chaperonin surface reveal a range of possible binding interactions.