4k87
Crystal structure of human prolyl-tRNA synthetase (substrate bound form)
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 PubMedAminoacyl-tRNA synthetases recognize cognate amino acids and tRNAs from their noncognate counterparts and catalyze the formation of aminoacyl-tRNAs. Halofuginone (HF), a coccidiostat used in veterinary medicine, exerts its effects by acting as a high-affinity inhibitor of the enzyme glutamyl-prolyl-tRNA synthetase (EPRS). In order to elucidate the precise molecular basis of this inhibition mechanism of human EPRS, the crystal structures of the prolyl-tRNA synthetase domain of human EPRS (hPRS) at 2.4 A resolution (hPRS-apo), of hPRS complexed with ATP and the substrate proline at 2.3 A resolution (hPRS-sub) and of hPRS complexed with HF at 2.62 A resolution (hPRS-HF) are presented. These structures show plainly that motif 1 functions as a cap in hPRS, which is loosely opened in hPRS-apo, tightly closed in hPRS-sub and incorrectly closed in hPRS-HF. In addition, the structural analyses are consistent with more effective binding of hPRS to HF with ATP. Mutagenesis and biochemical analysis confirmed the key roles of two residues, Phe1097 and Arg1152, in the HF inhibition mechanism. These structures will lead to the development of more potent and selective hPRS inhibitors for promoting inflammatory resolution. Conformational changes in human prolyl-tRNA synthetase upon binding of the substrates proline and ATP and the inhibitor halofuginone.,Son J, Lee EH, Park M, Kim JH, Kim J, Kim S, Jeon YH, Hwang KY Acta Crystallogr D Biol Crystallogr. 2013 Oct;69(Pt 10):2136-45. doi:, 10.1107/S0907444913020556. Epub 2013 Sep 20. PMID:24100331[4] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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