Single-Molecule Analyses Reveal Rhomboid Proteins Are Strict and Functional Monomers in the Membrane

摘要: Intramembrane proteases hydrolyze peptide bonds within the membrane as a regulatory paradigm that is conserved across all forms of cellular life. Many these enzymes are thought to be oligomeric, and their resulting quaternary interactions form basis regulation. However, technical limitations have precluded directly determining oligomeric state intramembrane in any membrane. Using single-molecule photobleaching, we determined structure 10 different rhomboid proteins (the largest superfamily proteases) six unrelated control parallel detergent micelle, planar supported lipid bilayer, whole-cell systems. Bacterial, parasitic, insect, human inactive pseudoproteases proved monomeric conditions but dimeric micelles. These analyses establish are, strict family rule, structurally functionally by nature dimers unphysiological.