Hierarchical cascades of instability govern the mechanics of coiled coils: helix unfolding precedes coil unzipping.

ABSTRACT: Coiled coils are a fundamental emergent motif in proteins found in structural biomaterials, consisting of α-helical secondary structures wrapped in a supercoil. A fundamental question regarding the thermal and mechanical stability of coiled coils in extreme environments is the sequence of events leading to the disassembly of individual oligomers from the universal coiled-coil motifs. To shed light on this phenomenon, here we report atomistic simulations of a trimeric coiled coil in an explicit water solvent and investigate the mechanisms underlying helix unfolding and coil unzipping in the assembly. We employ advanced sampling techniques involving steered molecular dynamics and metadynamics simulations to obtain the free-energy landscapes of single-strand unfolding and unzipping in a three

SUBMITTER: Hamed E 

PROVIDER: S-EPMC4104036 | biostudies-literature | 2014 Jul

REPOSITORIES: biostudies-literature