Nanobody-mediated control of long RSH Rel and RelA catalysis by restriction of their conformational landscape
Long RSH enzymes, Rel and RelA, are master regulators of bacterial (p)ppGpp alarmones levels. Bifunctional Rel transitions between a compact hydrolysis-competent (HD ON) state, a relaxed catalytically inactive (HD OFF/SYNTH OFF) state, and an elongated synthesis-competent (SYNTH ON) state, whereas RelA samples only the latter two. The distribution of these states is controlled by starved ribosomes
