Figure 2: tRNALeu is required for reversible TM84 inhibition of leucine activation.
From: Plant tumour biocontrol agent employs a tRNA-dependent mechanism to inhibit leucyl-tRNA synthetase
(a) TM84 inhibition of LeuRSAt (1 nM) ATP/PPi exchange reaction +/− tRNALeu (6.7 μM). Initial rate reaction conditions are LeuRSAt only (Δ), LeuRSAt with 1 μM TM84 (
), LeuRSAt with tRNALeu (▲), and LeuRSAt with tRNALeu and 50 nM TM84 (
). Error bars indicate standard deviation, n=3. (b) TM84 dose–response curves of LeuRSAt-catalysed ATP/PPi-exchange reaction in the absence () and presence () of tRNALeu. IC50 TM84>25 μM and IC50 TM84·tRNA<1 nM. (c) Effect of RNase treatment on LeuRSAt·tRNALeu·TM84 complex ATP/PPi exchange activity. Reaction conditions examined were LeuRSAt with tRNALeu (▲), LeuRSAt with tRNALeu and 250 nM TM84 (), preformed LeuRSAt·tRNALeu complex treated with RNase (
), and preformed LeuRSAt·tRNALeu·TM84 complex treated with RNase (
).
