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Publication Abstract from PubMed

The N-terminal anticodon-binding domain of the nondiscriminating aspartyl-tRNA synthetase (ND-AspRS) plays a crucial role in the recognition of both tRNAAsp and tRNAAsn. Here, the first X-ray crystal structure of the N-terminal domain of this enzyme (ND-AspRS1-104) from the human-pathogenic bacterium Helicobacter pylori is reported at 2.0 A resolution. The apo form of H. pylori ND-AspRS1-104 shares high structural similarity with the N-terminal anticodon-binding domains of the discriminating aspartyl-tRNA synthetase (D-AspRS) from Escherichia coli and ND-AspRS from Pseudomonas aeruginosa, allowing recognition elements to be proposed for tRNAAsp and tRNAAsn. It is proposed that a long loop (Arg77-Lys90) in this H. pylori domain influences its relaxed tRNA specificity, such that it is classified as nondiscriminating. A structural comparison between D-AspRS from E. coli and ND-AspRS from P. aeruginosa suggests that turns E and F (78GAGL81 and 83NPKL86) in H. pylori ND-AspRS play a crucial role in anticodon recognition. Accordingly, the conserved Pro84 in turn F facilitates the recognition of the anticodons of tRNAAsp (34GUC36) and tRNAAsn (34GUU36). The absence of the amide H atom allows both C and U bases to be accommodated in the tRNA-recognition site.

Crystal structure of the N-terminal anticodon-binding domain of the nondiscriminating aspartyl-tRNA synthetase from Helicobacter pylori.,Songsiriritthigul C, Suebka S, Chen CJ, Fuengfuloy P, Chuawong P Acta Crystallogr F Struct Biol Commun. 2017 Feb 1;73(Pt 2):62-69. doi:, 10.1107/S2053230X16020586. Epub 2017 Jan 19. PMID:28177315^[2]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.