Investigation of the utility of selective methyl protonation for determination of membrane protein structures.

摘要: Polytopic α-helical membrane proteins present one of the final frontiers for protein structural biology, with significant challenges causing severe under-representation in structure databank. However, advent hardware and methodology geared to study large molecular weight complexes, solution NMR is being increasingly considered as a tool studies these types proteins. One method that has potential facilitate utilizes uniformly deuterated samples protons reintroduced at or two methyl groups leucine, valine isoleucine. In this work we demonstrate spite increased proportion amino acids proteins, quality structures can be obtained from strategy similar all water soluble This partly attributed observation NOEs between residues within transmembrane helix did not have an impact on quality. Instead most important factors controlling accuracy were strength dihedral angle restraints imposed number unique inter-helical pairs constrained by NOEs. Overall results suggest accurate will arise identification helical segments utilization distance various sources maximize distribution long-range restraints.