Fig. 2.

Sequence specificity of RelQ inhibition by RNA. Here 24-nt-long mRNA(MF) (red) and its complementary antisense RNA (blue) were used as a positive and negative controls, respectively. Based on the two RNAs, we generated chimeras (A), cut-backs (B), and point mutants (C). We also reconstituted the inhibitory activity by adding two GG elements to otherwise inactive poly(A) RNA (D). To calculate the RelQ activity, the turnover rate (³H ppGpp synthesized per RelQ per minute) in the presence of RNA was divided by that in the absence of RNA. All reaction mixtures contained 100 nM RNA, 250 nM (62.5 nM tetramer) E. faecalis RelQ, 300 μM ³H GDP, and 1 mM ATP. Error bars represent SDs of the turnover estimates determined by linear regression. Each experiment was performed at least three times.