Biochemistry

The stringent response in bacteria is a stress response that is mediated by the signaling molecules guanosine tetraphosphate and pentaphosphate [(p)ppGpp], alarmones that are also directly related to virulence. Therefore, determination of (p)ppGpp levels is crucial for studying the stringent response. The protocol here outlines in a step-wise manner the detection of (p)ppGpp in the bacterium Streptomyces coelicolor during stringent response (Strauch et al., 1991) by thin layer chromatography (TLC). In the example shown here, stringent response is induced by addition of serine hydroxamate, an inhibitor of seryl tRNA synthetase. This protocol was first published in Molecular Microbiology (Sivapragasam and Grove, 2016).