MicroED structure of lipid-embedded mammalian mitochondrial voltage-dependent anion channel

Michael W. Martynowycz, Farha Khan, Johan Hattne, Jeff Abramson, and Tamir Gonen

Microcrystal electron diffraction (MicroED) is an electron cryo-microscopy (cryo-EM) method for determining structures using submicron crystals. Until now, determining structures of membrane proteins by MicroED required that the protein crystals be in a solution amenable to standard cryo-EM blotting and vitrification protocols. Here, we show that membrane protein microcrystals grown in a viscous bicelle mixture can become amenable to MicroED analyses by using modified blotting procedures combined with focused ion-beam milling. Our findings provide a basis for solving membrane protein structures using crystals embedded in a viscous media by MicroED.