Title: Structural basis for full-spectrum inhibition of translational functions on a tRNA synthetase. | Journal: Nature communications. 2015 Mar;6():6402 | Authors: Fang P, Yu X, Jeong SJ, Mirando A, Chen K, Chen X, Kim S, Francklyn CS, Guo M. | Abstract: The polyketide natural product borrelidin displays antibacterial, antifungal, antimalarial, anticancer, insecticidal and herbicidal activities through the selective inhibition of threonyl-tRNA synthetase (ThrRS). How borrelidin simultaneously attenuates bacterial growth and suppresses a variety of infections in plants and animals is not known. Here we show, using X-ray crystal structures and functional analyses, that a single molecule of borrelidin simultaneously occupies four distinct subsites within the catalytic domain of bacterial and human ThrRSs. These include the three substrate-binding sites for amino acid, ATP and tRNA associated with aminoacylation, and a fourth 'orthogonal' subsite created as a consequence of binding. Thus, borrelidin competes with all three aminoacylation substrates, providing a potent and redundant mechanism to inhibit ThrRS during protein synthesis. These results highlight a surprising natural design to achieve the quadrivalent inhibition of translation through a highly conserved family of enzymes. | See full PubMed entry: http://www.ncbi.nlm.nih.gov/pubmed/25824639 |
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