Pull-down assay of KREL1 with KREPA2. (A) Pull-down of KREPA2 wild-type (WT) with KREL1 full-length (FL), amino- and carboxy-terminal domains (NTD and CTD), and CTD truncations. (B) Pull-down of KREL1 WT and KREL1 ΔαΗ3 of the CTD with KREPA2 WT and domain mutants; deletion of αΗ1 (ΔαΗ1), deletion of OB-fold (ΔOB-fold) and ZnF mutant which substitutes four cysteine residues to alanine (ZnFC/A). (C) Pull-down assay of group mutations (GM) of αΗ3 of KREL1 and αΗ1 of KREPA2. The light gray illustrates the KREL1 αH3 mutants with the addition of KREPA2 WT, and the dark gray illustrates the KREPA2 αH1 group mutants with KREL1 WT. GMs are detailed next to the graph, including alanine substitutions of positively charged residues, negatively charged residues, and hydrophobic residues on each helix. Error bars represent SD obtained from three replicate experiments. (****) P < 0.0001, (***) P < 0.001, (**) P < 0.01, (*) P < 0.05.
