FIGURE 1:

Structural rearrangements within the DRP1 molecules upon nucleotide binding: (a) Cyanidioschyzon merolae Dnm1 crystal structure depicts a closed state of a DRP1 molecule. (b) Crystal structure of human DRP1 shows an open GTPase hinge from chain (A) where both the loops that constitute the GTPase hinge were ordered. (c) Cryo-EM structure of DRP1 determined with nucleotide and the MID49 receptor. The G-domain is rotated and loops L1N^S and L2^S are stabilized and visible. (d) Overlay of DRP1 dimers in the apo state (4BEJ, light shade, Fröhlich et al., 2013), the linear cryo-EM structure (5WP9, solid color), and the ring model (light shade, bent downward), as seen from Kalia et al. (2018), showing the range of movements exhibited by the G-BSE region relative to the stalk. The stalk is kept constant. (e, f) L1N^S and L2^S stabilization and interaction in dynamin family members: (e) Overlay of the region of the stalk that contains L1N^S and L2^S—from DRP1 cryo-EM structure (PDB ID: 5WP9), dynamin-3 crystal structure (PDB ID: 53AF), and MxB cryo-EM structure (PDB ID: 5UOT)—to depict the structural conservation of the region across dynamin family members. In each case, L1N^S and L2^S are stabilized by interdynamin and/or dynamin–receptor contacts. (f) L1N^S and L2^S mediate interdynamin contacts in the DRP1 cryo-EM structure (PDB ID: 5WP9).