Fig. 1: The side chain conformation of Y526 is determined by steric interactions with the surrounding amino acids.
From: Visualizing protein breathing motions associated with aromatic ring flipping
a, Crystal structure of wild-type JIP1-SH3, showing the conformation of Y526 and its stabilizing interactions with H493, V517, Q520 and A541. Dashed lines indicate CH–π (black) and π–π (red) interactions. b, Side chain conformation of Y526 in JIP1-SH3, illustrating the steric interactions between the δ1 nuclei of the aromatic ring and the backbone. c, PCA of a dataset comprising the size of the amino acid side chains at positions 493, 517 and 541 within SH3 domains that contain Y or F at position 526 (Extended Data Fig. 5b). Two groups are observed, which correspond to eclipsed (group 1) or staggered (group 2) conformations of the aromatic ring. JIP1-SH3 is indicated in blue; POSH-SH3-1 and POSH-SH3-4 are indicated in green; and SH3 domains for which crystal structures have been determined previously are shown in red. d, Crystal structure of POSH-SH3-1, showing a staggered conformation of Y172. e, Unbiased electron density maps (Fo–Fc) of Y172 and the surrounding residues in POSH-SH3-1. f, Crystal structure of POSH-SH3-4, showing an eclipsed conformation of F867. g, Unbiased electron density maps (Fo–Fc) of F867 and the surrounding residues in POSH-SH3-4. h, i, Results of the PCA, illustrating the size and nature of the residues that surround the aromatic ring in position 526 in group 1 (h) and group 2 (i) SH3 domains. The size of the spheres in each position is proportional to the average size (nav) of the amino acid side chain across group members.
