Structural evidence for the roles of divalent cations in actin polymerization and activation of ATP hydrolysis.

ABSTRACT: The structure of the actin filament is known at a resolution that has allowed the architecture of protein components to be unambiguously assigned. However, fully understanding the chemistry of the system requires higher resolution to identify the ions and water molecules involved in polymerization and ATP hydrolysis. Here, we find experimental evidence for the association of cations with the surfaces of G-actin in a 2.0-Å resolution X-ray structure of actin bound to a Cordon-Bleu WH2 motif and in previously determined high-resolution X-ray structures. Three of four reoccurring divalent cation sites were stable during molecular dynamics (MD) simulations of the filament, suggesting that these sites may play a functional role in stabilizing the filament. We modeled the water coordination at t

SUBMITTER: Scipion CPM 

PROVIDER: S-EPMC6187199 | biostudies-literature | 2018 Oct

REPOSITORIES: biostudies-literature