6ni7

Pseudomonas fluorescens isocyanide hydratase at 277 K

spinqualitylabelsall models 6ni7, resolution 1.15Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 6ni7 is a 2 chain structure with sequence from Pseudomonas protegens Pf-5. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.15Å Ligands: CSO Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function Q4K977_PSEF5 Publication Abstract from PubMed How changes in enzyme structure and dynamics facilitate passage along the reaction coordinate is a fundamental unanswered question. Here, we use time-resolved mix-and-inject serial crystallography (MISC) at an X-ray free electron laser (XFEL), ambient-temperature X-ray crystallography, computer simulations, and enzyme kinetics to characterize how covalent catalysis modulates isocyanide hydratase (ICH) conformational dynamics throughout its catalytic cycle. We visualize this previously hypothetical reaction mechanism, directly observing formation of a thioimidate covalent intermediate in ICH microcrystals during catalysis. ICH exhibits a concerted helical displacement upon active-site cysteine modification that is gated by changes in hydrogen bond strength between the cysteine thiolate and the backbone amide of the highly strained Ile152 residue. These catalysis-activated motions permit water entry into the ICH active site for intermediate hydrolysis. Mutations at a Gly residue (Gly150) that modulate helical mobility reduce ICH catalytic turnover and alter its pre-steady-state kinetic behavior, establishing that helical mobility is important for ICH catalytic efficiency. These results demonstrate that MISC can capture otherwise elusive aspects of enzyme mechanism and dynamics in microcrystalline samples, resolving long-standing questions about the connection between nonequilibrium protein motions and enzyme catalysis. Mix-and-inject XFEL crystallography reveals gated conformational dynamics during enzyme catalysis.,Dasgupta M, Budday D, de Oliveira SHP, Madzelan P, Marchany-Rivera D, Seravalli J, Hayes B, Sierra RG, Boutet S, Hunter MS, Alonso-Mori R, Batyuk A, Wierman J, Lyubimov A, Brewster AS, Sauter NK, Applegate GA, Tiwari VK, Berkowitz DB, Thompson MC, Cohen AE, Fraser JS, Wall ME, van den Bedem H, Wilson MA Proc Natl Acad Sci U S A. 2019 Dec 4. pii: 1901864116. doi:, 10.1073/pnas.1901864116. PMID:31801874 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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