¹H, ¹⁵N, ¹³C backbone resonance assignments of human phosphoglycerate kinase in a transition state analogue complex with ADP, 3-phosphoglycerate and magnesium trifluoride

Human phosphoglycerate kinase (PGK) is an energy generating glycolytic enzyme that catalyses the transfer of a phosphoryl group from 1,3-bisphosphoglycerate (BPG) to ADP producing 3-phosphoglycerate (3PG) and ATP. PGK is composed of two α/β Rossmann-fold domains linked by a central α-helix and the active site is located in the cleft formed between the N-domain which binds BPG or 3PG, and the C-domain which binds the nucleotides ADP or ATP. Domain closure is required to bring the two substrates into close proximity for phosphoryl transfer to occur, however previous structural studies involving a range of native substrates and substrate analogues only yielded open or partly closed PGK complexes. X-ray crystallography using magnesium trifluoride (MgF₃ ⁻) as a isoelectronic and near-isosteric mimic of the transferring phosphoryl group (PO₃ ⁻), together with 3PG and ADP has been successful in trapping human PGK in a fully closed transition state analogue (TSA) complex. In this work we report the ¹H, ¹⁵N and ¹³C backbone resonance assignments of human PGK in the solution conformation of the fully closed PGK:3PG:MgF₃:ADP TSA complex. Assignments were obtained by heteronuclear multidimensional NMR spectroscopy. In total, 97% of all backbone resonances were assigned in the complex, with 385 out of a possible 399 residues assigned in the ¹H–¹⁵N TROSY spectrum. Prediction of solution secondary structure from a chemical shift analysis using the TALOS-N webserver is in good agreement with the published X-ray crystal structure of this complex.