Membrane protein production for structural analysis

Abstract

Membrane proteins (MPs) account for roughly 30% of all open reading frames in fully sequenced genomes. However, to date, atomic structures have so far been obtained for only 474 integral MPs, with 150 new structures determined in the past 2 years. Only 10% of the unique integral MP structures are derived from vertebrates. The majority of integral MPs is present in tissues at very low concentration, making production of recombinant proteins in heterologous systems suitable for large-scale production a prerequisite for structural studies. Since the first atomic structures of recombinant mammalian integral MPs published in 2005 (Jidenko et al., Proc Natl Acad Sci U S A 102:11687-11691, 2005; Long et al., Science 309:897-903, 2005), the structures of 37 recombinant mammalian integral MPs, of which 20 belong to the G protein-coupled receptors family, have been solved. This chapter reviews the advances in heterologous expression systems, stabilization tools, and structural methods that contributed to the growing number of recombinant mammalian integral MP structures solved this past years.