Research Paper Volume 16, Issue 6 pp 5501—5525

Structural insights into human EMC and its interaction with VDAC

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Figure 3. Cryo-EM structure of human EMC-VDAC1 complex. (A) The cryo-EM density map and ribbon diagram of human EMC-VDAC1 complex, color-coded by subunit. (B) The top view of the complex showing the interaction between VDAC1 and EMC. (C) A close-up view of the EMC3-VDAC1 interface highlighted in the pink dashed box in (B). Charged amino acids Lys42, Lys112, and Asp103 of EMC3 respectively interact with residues Glu66, Ser35, and Lys252 in the cytosolic loops of VDAC1. (D) Glu73VDAC1 is buried inside a hydrophilic pocket formed by Lys112, Thr116 and Gln117 of EMC3. (E) A zoom-in view of the EMC4-VDAC1 interface indicated by the orange dashed box in (B). The interaction involves hydrogen bonds formed by Asn79 and Asn106 of VDAC1 with Ser95 and Thr93 of EMC4, respectively. (F) The hydrophobic interface between EMC7 and VDAC1, mediated by Met167, Met168 and Leu178 of EMC7, and Ile85, Phe99 and Leu91 of VDAC1. (G) A close-up view of TMHEMC7. This segment adopts a bent conformation, with a short helix adjacent to TMH2EMC3 followed by another helix turning away from the hydrophilic vestibule.