Fusion Partner Toolchest for the Stabilization and Crystallization of G Protein-Coupled Receptors

Summary Structural studies of human G protein-coupled receptors (GPCRs) have recently been accelerated through the use of a fusion partner that was inserted into the third intracellular loop. Using chimeras of the human β 2 -adrenergic and human A 2A adenosine receptors, we present the methodology and data for the initial selection of an expanded set of fusion partners for crystallizing GPCRs. In particular, use of the thermostabilized apocytochrome b 562 RIL as a fusion partner displays certain advantages over previously utilized fusion proteins, resulting in a significant improvement in stability and structure of GPCR-fusion constructs.