Structural topology of phospholamban pentamer in lipid bilayers by a hybrid solution and solid-state NMR method.

ABSTRACT: Phospholamban (PLN) is a type II membrane protein that inhibits the sarcoplasmic reticulum Ca(2+)-ATPase (SERCA), thereby regulating calcium homeostasis in cardiac muscle. In membranes, PLN forms pentamers that have been proposed to function either as a storage for active monomers or as ion channels. Here, we report the T-state structure of pentameric PLN solved by a hybrid solution and solid-state NMR method. In lipid bilayers, PLN adopts a pinwheel topology with a narrow hydrophobic pore, which excludes ion transport. In the T state, the cytoplasmic amphipathic helices (domains Ia) are absorbed into the lipid bilayer with the transmembrane domains arranged in a left-handed coiled-coil configuration, crossing the bilayer with a tilt angle of approximately 11° with respect to the membrane

SUBMITTER: Verardi R 

PROVIDER: S-EPMC3107283 | biostudies-literature | 2011 May

REPOSITORIES: biostudies-literature