Ca2+ Selective filter in N.crassa MCU. (A) Top and side view of Asp (D355) ring in the pore of N.crassa MCU. It’s shown that side chain of D355 is in the shape of facing IMS at a side view. (B) Top and side view of Glu (E358) ring in the pore of N.crassa MCU. At top view, it’s shown clearly that side chain of E358 is toward to Ca2+ (red circle) to coordinate them. (C) Sequence alignment of DxxE motif from human to fungi. The two acidic residues in DxxE motif are represented in red and the two residues in cyan are those that exist only in the N.crassa MCU in DxxE motif. (D) Interactions made between DxxE motif and neighboring residues; hydrogen bonds are marked with red dashes and van der Waals interaction is marked with black dash.
