Membrane protein biogenesis by the EMC.

The endoplasmic reticulum (ER) membrane protein complex (EMC) was identified over a decade ago in a genetic screen for ER protein homeostasis. The EMC inserts transmembrane domains (TMDs) with limited hydrophobicity. Two recent cryo-EM structures, and a third model based on partial high- and low-resolution structures, suggest how this is accomplished.