Skip to main content
. Author manuscript; available in PMC: 2009 Mar 21.
Published in final edited form as: J Mol Biol. 2008 Jan 26;377(2):551–564. doi: 10.1016/j.jmb.2008.01.042

Figure 4.

Figure 4

Inhibition of mutant RNAPs by ppGpp in the presence of DksA. Single-round transcription was performed as described (see Materials and Methods) with neither ppGpp nor DksA (first lane in each panel), with ppGpp alone (100 μM; second lane in each panel), with DksA alone (third lane in each panel; for concentrations see Materials and Methods), or with both together (fourth lane in each panel). WT = wild-type RNAP. β′ N458S, β′ E925A, and β′ Q929A RNAPs (not shown) exhibited transcription elongation defects, resulting in some incomplete extension products under these conditions (see Materials and Methods).