Letter reSeArCH
Extended Data Fig. 6 | Mgm1 tetramers in crystal and membrane
lattices. a–d, Mgm1 assemblies in the presence of GTPγS on the
outer (a, c) and inner surface (b, d) of a membrane tube. a, b, Surface
representations of flexibly fitted Mgm1 molecules, showing their
arrangement in the protein lattice. c, d, Fit into the corresponding
cryo-ET volume. Note that the membrane density and, consequently, the
paddle–membrane contact, is more prominent in the GTPγS-bound form
compared with the nucleotide-free form (Figs. 4 b, 5a). e, Comparison
of Mgm1 tetramers in the crystal lattice (blue) with tetramers fitted to
the subtomogram average volumes obtained for the external (orange)
and internal surface lattice (pink). Fitting the paddle and the BSE and
G domains required only minor rearrangements. f, Tetramers in the
crystal lattice pack into a linear assembly. Crystal contacts between two
tetramers are mediated by the BSE domain of one tetramer (blue) and the
stalk domain of the neighbouring tetramer (grey), resulting in an open
interface-1. When comparing intra- and inter-tetramer interactions, BSE
domain residues E533, E534 and Y537 in α 2 B bind to different sites of the
adjacent stalks.