3pr2

Tryptophan synthase indoline quinonoid structure with F9 inhibitor in alpha site

spinqualitylabelsall models 3pr2, resolution 1.85Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 3pr2 is a 2 chain structure with sequence from Salmonella enterica subsp. enterica serovar typhimurium. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: 7MN, CS, F9F Gene: STM1727, trpA (Salmonella enterica subsp. enterica serovar Typhimurium), STM1726, trpB (Salmonella enterica subsp. enterica serovar Typhimurium) Activity: Tryptophan synthase, with EC number 4.2.1.20 Resources: FirstGlance, OCA, RCSB, PDBsum Function [TRPA_SALTY] The alpha subunit is responsible for the aldol cleavage of indoleglycerol phosphate to indole and glyceraldehyde 3-phosphate. [TRPB_SALTY] The beta subunit is responsible for the synthesis of L-tryptophan from indole and L-serine. Publication Abstract from PubMed Chemical-level details such as protonation and hybridization state are critical for understanding enzyme mechanism and function. Even at high resolution, these details are difficult to determine by X-ray crystallography alone. The chemical shift in NMR spectroscopy, however, is an extremely sensitive probe of the chemical environment, making solid-state NMR spectroscopy and X-ray crystallography a powerful combination for defining chemically detailed three-dimensional structures. Here we adopted this combined approach to determine the chemically rich crystal structure of the indoline quinonoid intermediate in the pyridoxal-5'-phosphate-dependent enzyme tryptophan synthase under conditions of active catalysis. Models of the active site were developed using a synergistic approach in which the structure of this reactive substrate analogue was optimized using ab initio computational chemistry in the presence of side-chain residues fixed at their crystallographically determined coordinates. Various models of charge and protonation state for the substrate and nearby catalytic residues could be uniquely distinguished by their calculated effects on the chemical shifts measured at specifically (13)C- and (15)N-labeled positions on the substrate. Our model suggests the importance of an equilibrium between tautomeric forms of the substrate, with the protonation state of the major isomer directing the next catalytic step. X-ray and NMR crystallography in an enzyme active site: the indoline quinonoid intermediate in tryptophan synthase.,Lai J, Niks D, Wang Y, Domratcheva T, Barends TR, Schwarz F, Olsen RA, Elliott DW, Fatmi MQ, Chang CE, Schlichting I, Dunn MF, Mueller LJ J Am Chem Soc. 2011 Jan 12;133(1):4-7. Epub 2010 Dec 10. PMID:21142052 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Tryptophan synthase

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