Membrane protein structure determination is a difficult task for structural biologists. Membrane proteins comprise 30% of the proteome. However, only ~30 unique structures have been determined, making their contribution to the protein data bank less than 0.5%. The majority of membrane proteins are transmembrane helical bundles, but of the known structures roughly half are beta-barrel proteins, which are limited to the outer membrane of bacteria, mitochondria, and chloroplasts. This study targets helical membrane proteins with two, three, and four predicted transmembrane segments for NMR structure determination in order to significantly diversify the different types of membrane protein structures known. Defective membrane proteins have been identified in many diseases due to misfolding and loss of function making them targets for drug design. Structural information could advance the effectiveness of these drug pursuits. In addition, more helical transmembrane structures will aid in the understanding of membrane protein stability and increase the likelihood of predicting membrane protein structures.
