. Author manuscript; available in PMC: 2018 Jan 1.

Published in final edited form as: Trends Genet. 2016 Dec 5;33(1):58–67. doi: 10.1016/j.tig.2016.11.002

Table 1.

Comparing ppGpp mediated response to starvation and genotoxic stress

	Amino acid starvation	Genotoxic Shock
Common Inducer	Amino acid analogs (e.g: SHX)	DNA modifiers
Response signal	Uncharged tRNA at A-site	Unknown
Response sensor	RelA	RelA or SpoT
Peak Time (min)	≤10 min	≤15 min
Duration	Hours	Minutes
Fold induction ppGpp	~70	~20
Primary target	Initiating RNAP (stable RNA genes)	Elongating RNAP
Phenotype of relAspoT	Poor recovery from starvation	Poor survival of genotoxic stress