Mg~(2+) concentration-dependence of 70S ribosomal-protein dynamics revealed by H/D exchange and mass spectrometry

摘要

70S ribosome from E. coli is a super-macro complex (MW: 2.3 MDa) composed of 30S and 50S subunits, whose dissociation and activity depend on Mg~(2+) concentration. How do ribosomal proteins more than fifty behave in function and dissociation processes? Although it is difficult to detect the dynamics of a super-macro complex in detail, we have succeeded in analyzing the effect of Mg~(2+) on the structural flexibility and solvent accessibility of 52 ribosomal proteins in 70S ribosome by the combination of the hydrogen/deuterium (H/D) exchange and MALDI mass spectrometry.