Figure 3. Pull‐down experiments to test the contribution of individual MICU2 residues to the interaction with MICU1 in the apo and Ca²⁺‐bound states.

• A, B
  MICU2_WT (A) and MICU2_K172A (B) were pulled down by GST‐MICU1 in both the absence and presence of 2 mM Ca²⁺.
• C, D
  MICU2_EF1^mut was not pulled down by GST‐MICU1 in the presence of 2 mM Ca²⁺ (C), while MICU2_EF2^mut was pulled down by GST‐MICU1 in both the absence and presence of 2 mM Ca²⁺ (D).
• E, F
  MICU2_R352A was not pulled down by GST‐MICU1 in the absence of 2 mM Ca²⁺ (E), while MICU2_E329A was pulled down by GST‐MICU1 in both the absence and presence of 2 mM Ca²⁺ (F).
• G
  MICU2_D185A was partially pulled down by GST‐MICU1 in the presence of Ca²⁺, while they showed a strong interaction in the absence of 2 mM Ca²⁺.
• H
  MICU2_E196K was not pulled down by GST‐MICU1 in the presence of 2 mM Ca²⁺, while a strong interaction was observed in the absence of 2 mM Ca²⁺.