Klein, AlexanderRovó, PetraSakhrani, Varun V.Wang, YangyangHolmes, Jacob B.Liu, ViktoriiaSkowronek, PatriciaKukuk, LauraVasa, Suresh K.Güntert, PeterMueller, Leonard J.Linser, Rasmus2026-01-152026-01-152022-01-20http://hdl.handle.net/2003/44667NMR chemical shifts provide detailed information on the chemical properties of molecules, thereby complementing structural data from techniques like X-ray crystallography and electron microscopy. Detailed analysis of protein NMR data, however, often hinges on comprehensive, site-specific assignment of backbone resonances, which becomes a bottleneck for molecular weights beyond 40 to 45 kDa. Here, we show that assignments for the (2x)72-kDa protein tryptophan synthase (665 amino acids per asymmetric unit) can be achieved via higher-dimensional, proton-detected, solid-state NMR using a single, 1-mg, uniformly labeled, microcrystalline sample. This framework grants access to atom-specific characterization of chemical properties and relaxation for the backbone and side chains, including those residues important for the catalytic turnover. Combined with first-principles calculations, the chemical shifts in the β-subunit active site suggest a connection between active-site chemistry, the electrostatic environment, and catalytically important dynamics of the portal to the β-subunit from solution.enProceedings of the National Academy of Sciences of the United States of America; 119(4)https://creativecommons.org/licenses/by-nc-nd/4.0/Solid-state NMRNMR crystallographyTryptophan synthasePLP- dependent enzymesTautomerism540ResearchArticleFestkörper-NMR-SpektroskopiePyridoxalphosphatEnzymSynthasenTryptophanTautomerie