Аннотация:Significance The first structural studies, to our knowledge, of a reticulon homology domain (RHD), which is essential for maintaining smooth endoplasmic reticulum (ER) tubules and the edges of ER sheets, are described. We show here that the RHD of the protein Yop1p from the YOP1 gene has hydrophobic helices long enough to cross the membrane fully but contains a previously uncharacterized amphipathic helix (APH) that is necessary for membrane tubule formation. The APH is highly conserved in its amino acid properties and its location relative to the RHD both in the DP1 (deleted in polyposis) and reticulon families. These results place the DP1/reticulon proteins into the large and growing class of membrane-remodeling proteins that use APHs to influence membrane curvature.
