How Force Might Activate Talin's Vinculin Binding Sites: SMD Reveals a Structural Mechanism
Figure 4
Side Chain Hydrogen Bonds Formed between the α-Helix Subbundles, H1–H5, H6–H8, H9–H12 in Talin1 as Identified in the Simulations
(A) Location of interbundle side chain hydrogen bonds is shown schematically in the equilibrated structure (Connection [black] of the Cα-atoms of the interacting residues [shown in yellow]).
(B) Stability of interbundle hydrogen bonds: the bond length fluctuations are given at a scale of 2-4 Å, beyond which the bond is considered broken. In all the cases where amino acid side chains provide multiple donors or acceptors, the shortest of the bonds formed is shown. Multiple bonding partners are listed. The fluctuations of bonds connecting the helix bundles of H1–H5 to H6–H8 are shown in blue, while the ones connecting the H6–H8 to H9–H12 bundles are shown in green. The fully conserved residues among the talin1 and talin2 from human, mouse, and chicken (Figure S1) are written in green, and non-conserved residues in red.