Fig. 6

Crystal structure of vinculin tail (Vin-T) bound to paxillin peptides LD1 and LD2. (A) The asymmetric unit contains 4 Vin-T molecules (chains A and C colored in green; B and D in blue), 2 LD1 (chains G and H in yellow) and 2 LD2 peptides (chains E and F in orange). A 2-fold non-crystallographic symmetry axis (perpendicular to the plane of the left view) relates molecules of the same color to each other. Two perpendicular views are shown. (B) The LD1 and LD2 peptides are well defined by electron density maps. The blue mesh represents 2Fo-Fc electron density countered at 1σ. (C) Close-ups of Vin-T (chain A) interacting with LD1 (chain G) (left panel), Vin-T (A) interacting with LD2 (E) (middle panel) and Vin-T (B) interacting with LD2 (E) (right panel). (D) Superposition of Vin-T (green ribbon) bound to one LD1 (space-fill with carbons in yellow) and two LD2 peptides (space-fill with carbons in orange) with full-length vinculin (PDB: 1ST6) (grey, with the head domain, Vin-H, in space-fill and the tail domain as ribbon). The LD1 and two LD2 peptides are interacting with Vin-T via the three sites shown in (C) and the Vin-T and LD chain IDs for the interactions shown are indicated. (E) Superposition of Vin-T (green) bound to one LD1 and two LD2 peptides (coloring and labelling as in D) with the cryo-EM structure of Vin-T bound to F-actin (PDB: 3JBI) (grey, with Vin-T as ribbon and F-actin in space-fill). The position of the LD1 peptide bound to Vin-T is indicated, but mostly obstructed from the view