TABLE 2.

Chemical half-lives of bulk mRNA in various S. coelicolor and E. coli strains

Strain	Conditions or description	Mean half-life (min) ± SEMa
S. coelicolor
M600	Parental strain, exponential phase	3.2 ± 0.2
	Parental strain, stationary phase	5.7 ± 0.6
M570	relA-null mutant, exponential phase	8.9 ± 0.8
	relA-null mutant, stationary phase	7.2 ± 0.7
M653	Strain M570 with inducible relA with no thiostrepton	6.6 ± 0.9
	Strain M570 with inducible relA plus thiostrepton	11.8 ± 1.6
JSE571	With pIJ8600, no thiostrepton	6.8 ± 0.8
	With pIJ8600 plus thiostrepton	5.7 ± 0.9
E. coli
CF1648	relA+; exponential phase	2.6 ± 0.3
	relA+; stationary phase	2.2 ± 0.3
CF1652	relA-null mutant, exponential phase	2.3 ± 0.2
	relA-null mutant, stationary phase	3.0 ± 0.2

^aHalf-lives were calculated from the data shown in Fig. 5 or from similar plots in the case of the E. coli measurements.