Whole Ribosome NMR: Dipolar Couplings and Contributions to Whole Cells
Year: 2017
Type: article
Abstract: Solid-state NMR is a powerful tool for quantifying chemical composition and structure in complex assemblies and even whole cells. We employed N{P} REDOR NMR to obtain atomic-level distance propensities in intact 15 N-labeled E. coli ribosomes. The experimental REDOR dephasing of shift-resolved lysyl amine nitrogens by phosphorus was comparable to that expected from a calculation of N–P distances involving the lysines included in the crystal structure coordinates. Among the nitrogen contributions to the REDOR spectra, the strongest dephasing emerged from the dipolar couplings to phosphorus involving nitrogen peaks ascribed primarily to rRNA, and the weakest dephasing arose from protein amide nitrogens. This approach is applicable to any macromolecular system and provides quantitative comparisons of distance proximities between shift-resolved nuclei of one type and heteronuclear dephasing spins. Enhanced molecular specificity could be achieved through the use of spectroscopic filters or specific labeling. Furthermore, ribosome 13 C and 15 N CPMAS spectra were compared with those of whole cells from which the ribosomes were isolated. Whole-cell signatures of ribosomes were identified and should be of value in comparing overall cellular ribosome content in whole-cell samples.
Institution: Stanford University
Language: English
Subfield: Spectroscopy
Field: Chemistry
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2756386316