5vad
Crystal structure of human Prolyl-tRNA synthetase (PRS) in complex with inhibitor
Structural highlights
FunctionSYEP_HUMAN Catalyzes the attachment of the cognate amino acid to the corresponding tRNA in a two-step reaction: the amino acid is first activated by ATP to form a covalent intermediate with AMP and is then transferred to the acceptor end of the cognate tRNA. Component of the GAIT (gamma interferon-activated inhibitor of translation) complex which mediates interferon-gamma-induced transcript-selective translation inhibition in inflammation processes. Upon interferon-gamma activation and subsequent phosphorylation dissociates from the multisynthetase complex and assembles into the GAIT complex which binds to stem loop-containing GAIT elements in the 3'-UTR of diverse inflammatory mRNAs (such as ceruplasmin) and suppresses their translation.[1] [2] [3] Publication Abstract from PubMedProlyl-tRNA synthetase (PRS) is a member of the aminoacyl-tRNA synthetase family of enzymes and catalyzes the synthesis of prolyl-tRNAPro using ATP, l-proline, and tRNAPro as substrates. An ATP-dependent PRS inhibitor, halofuginone, was shown to suppress autoimmune responses, suggesting that the inhibition of PRS is a potential therapeutic approach for inflammatory diseases. Although a few PRS inhibitors have been derivatized from natural sources or substrate mimetics, small-molecule human PRS inhibitors have not been reported. In this study, we discovered a novel series of pyrazinamide PRS inhibitors from a compound library using pre-transfer editing activity of human PRS enzyme. Steady-state biochemical analysis on the inhibitory mode revealed its distinctive characteristics of inhibition with proline uncompetition and ATP competition. The binding activity of a representative compound was time-dependently potentiated by the presence of l-proline with Kd of 0.76 nM. Thermal shift assays demonstrated the stabilization of PRS in complex with l-proline and pyrazinamide PRS inhibitors. The binding mode of the PRS inhibitor to the ATP site of PRS enzyme was elucidated using the ternary complex crystal structure with l-proline. The results demonstrated the different inhibitory and binding mode of pyrazinamide PRS inhibitors from preceding halofuginone. Furthermore, the PRS inhibitor inhibited intracellular protein synthesis via a different mode than halofuginone. In conclusion, we have identified a novel drug-like PRS inhibitor with a distinctive binding mode. This inhibitor was effective in a cellular context. Thus, the series of PRS inhibitors are considered to be applicable to further development with differentiation from preceding halofuginone. Discovery of a novel prolyl-tRNA synthetase inhibitor and elucidation of its binding mode to the ATP site in complex with l-proline.,Adachi R, Okada K, Skene R, Ogawa K, Miwa M, Tsuchinaga K, Ohkubo S, Henta T, Kawamoto T Biochem Biophys Res Commun. 2017 Jun 24;488(2):393-399. doi:, 10.1016/j.bbrc.2017.05.064. Epub 2017 May 10. PMID:28501621[4] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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