Fig. 3: The cooperative binding of RM-A and l-isoleucine or Ile-AMP.
From: Inhibitory mechanism of reveromycin A at the tRNA binding site of a class I synthetase
a Close-up view of the interactions between RM-A and Ile-AMP. Ile-AMP and RM-A and residues F48, F191 and W529, which form hydrophobic stacking interactions, are displaced as spherical models. The water-mediated H-bonding interactions are shown as red dashed lines. b Thermal melting curves of ScIleRS in the presence of different ligands. RM-A alone could improve the Tm of ScIleRS by approximately 7 °C. Moreover, RM-A could co-bind with l-isoleucine and Ile-AMS but not ATP. c Thermal shift curves of SaIleRS in the presence of different ligands revealed that RM-A could not bind to SaIleRS, even in the presence of l-isoleucine or the intermediate analogue Ile-AMS. d–g ITC titrations of RM-A to apo ScIleRS (d) or ScIleRS protein presaturated with Ile-AMS (e), l-isoleucine (f) or ATP (g). The binding isotherms were fitted to a single-site model.
