NMR Structure and Dynamics Studies of Yeast Respiratory Supercomplex Factor 2

The Saccharomyces cerevisiae respiratory supercomplex factor 2 (Rcf2) is a 224-residue protein located in the mitochondrial inner membrane where it involved formation of supercomplexes composed cytochrome bc1 and c oxidase. We previously demonstrated that Rcf2 forms dimer dodecylphosphocholine micelles, here we report solution NMR structure this dimer. Each monomer has two soluble α helices five putative transmembrane (TM) helices, including an unexpectedly charged TM helix at C terminus, which mediates formation. NOE contacts indicate presence inter-monomer salt bridges hydrogen bonds interface, stabilize structure. Moreover, chemical shift change mapping upon lipid titrations as well molecular dynamics analysis reveal possible structural changes embedding into native environment. Our results contribute to understanding regulation.