Structural Basis for the Recognition of Cellular mRNA Export Factor REF by Herpes Viral Proteins HSV-1 ICP27 and HVS ORF57
Figure 2
Identifying interaction sites within REF, ORF57 and ICP27 constructs via different NMR parameters.
The detailed data is presented in SI. Purple solid and broken bars mark residues with large and moderate reduction of mobility upon binding, respectively, as evidenced by the increase in 15N{1H} NOE. Orange stars mark residues with amide signals broadened beyond detection in the complex. Large and moderate chemical shift changes (δCS) of amide signals for each ligand as labelled are shown as solid and broken bars, respectively. Red bars mark residues forming direct inter-molecular NOE contacts in REF-ICP27 complex. (A) Changes in REF54–155 induced by addition of ICP27103–138 and ORF578–120. Position of secondary structure elements of REF (β-sheets, α-helices and loops) is shown in relation to its sequence. ICP27 and ORF57 bind on the same site on the REF RRM domain, with α-helices 1 and 2 and adjacent loop regions. (B) Changes in ORF578–120 upon addition of REF54–155. The main REF-interaction site is mapped to residues 103–120. (C) Changes in ICP27103–138 induced by addition of REF54–155. The REF-binding site is mapped to residues 104-112.