The RelA hydrolase domain acts as a molecular switch for (p)ppGpp synthesis

Abstract

Sinha and Winther show that the Escherichia coli RelA inactive hydrolase domain modulates the activity of the synthetase domain. RelA produces (p)ppGpp in γ-proteobacteria; using mutagenesis screening and functional studies, the authors demonstrate that the H loop region in the RelA hydrolase domain acts as a molecular switch to regulate the synthetase domain activity of the enzyme.