FIG. 5.

Rsm28p is peripherally associated with mitochondrial membranes. Mitochondria (M) purified from a strain expressing Rsm28p-HA (NAB97) were sonicated (Sonic.) and separated into a membrane pellet (P) and soluble supernatant (S) by centrifugation. An aliquot of this membrane fraction was extracted with sodium carbonate (pH 11.5) (Alk.), followed by centrifugation to separate pelleted integral membrane proteins (P) from solubilized proteins in the supernatant (S). Samples were resolved by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, immunoblotted, and probed with anti-HA antibody (Rsm28p-HA), anti-citrate synthase as a matrix marker (CS), anti-Cox2p as an integral inner membrane marker (Cox2p), and anti-Mrp13p (Mrp13p) as a mitochondrial ribosomal marker.