Membrane proteins: the 'Wild West' of structural biology.
Historically, the task of determining the structure of membrane proteins has been hindered by experimental difficulties associated with their lipid-embedded domains. Here, we provide an overview of recently developed experimental and predictive tools that are changing our view of this largely unexplored territory - the 'Wild West' of structural biology. Crystallography, single-particle methods and atomic force microscopy are being used to study huge membrane proteins with increasing detail. Solid-state nuclear magnetic resonance strategies provide orientational constraints for structure determination of transmembrane (TM) alpha-helices and accurate measurements of intramolecular distances, even in very complex systems. Longer distance constraints are determined by site-directed spin-labelling electron paramagnetic resonance, but current labelling strategies still constitute some limitation. Other methods, such as site-specific infrared dichroism, enable orientational analysis of TM alpha-helices in aligned bilayers and, combined with novel computational and predictive tools that use evolutionary conservation data, are being used to analyze TM alpha-helical bundles.
Torres
Jaume
J
School of Biological Sciences, Nanyang Technological University, 637616, Singapore. jtorres@ntu.edu.sg
Stevens
Tim J
TJ
Samsó
Montserrat
M
D002942:Circular Dichroism / Q000379:methods; D018360:Crystallography, X-Ray; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods; D008565:Membrane Proteins / Q000737:chemistry* / Q000378:metabolism; D018625:Microscopy, Atomic Force; D008958:Models, Molecular; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary
D008565:Membrane Proteins