Fig. 7: Arf1 internal hydrogen bond network is destabilized in the myrArf1:PH complex.
From: An active allosteric mechanism in ASAP1-mediated Arf1 GTP hydrolysis redefines PH domain function
A (Top) Changes in the hydrogen bond network linking Glu54, Thr44 and Lys38 in Arf1 (left) upon interaction with wt PH (right) highlighting the centrality of Glu54. H-bond network within Arf (grey line) or to PH (green line). Thickness of the line indicates the propensity of the H-bond. (Bottom) Cartoon depiction of Arf illustrating the spatial arrangement of key residues and the interplay between the hydrogen bond network and conformational changes in switch 1. Images created using Chimera56. B Stack of rows extracted from a 1H-13C HMQC experiment along the proton dimension of Val43 (myrArf1) in the absence (a) or in the presence of wt ASAP1 PH (b), ΔN14ASAP1 PH (c) or ΔN9ASAP1 PH (d). C Effect on GAP activity assays of selected mutations on Arf1 (blue) and ASAP1 PH (yellow). C50 values (the concentration of PZA required to achieve 50% of GTP hydrolysis in 3 min) from each independent experiment are shown with 4 ≤ n ≤ 7. Error bars represent standard deviation. ns, not significant with p = 0.8251 and 0.4128 for the E441R and E441A mutants, respectively; ****, p < 0.00001 via one-way ANOVA with repeated measures (and mixed effects) and Dunnett’s multiple comparisons test against WT. Source data are provided as a Source data file.
