Fig. 4: AlpA interacts with the β-flap and σ70 region 1.1 of RNAP.
From: Control of a programmed cell death pathway in Pseudomonas aeruginosa by an antiterminator
a Diagram of bacterial two-hybrid assay used to test whether AlpA interacts with portions of RNAP. Diagram depicts how the interaction between AlpA (green), fused to the α-N-terminal domain and linker (α-NTD), and the RNAP domain (gray), fused to the bacteriophage λCI protein, activates transcription from the test promoter placOL2-62, which bears the λ operator OL2 centered 62 bp upstream of the start site of the lac core promoter driving lacZ. b Results of β-galactosidase assays performed with cells that contained plasmids directing the synthesis of the indicated proteins under the control of (IPTG)-inducible promoters; cells were grown in the presence of 5 µM IPTG. Values and error bars reflect mean ± SD of n = 3 biological replicates in technical duplicate. Two-tailed, unpaired, unequal variance t-tests were used to calculate p-values between indicated samples. λCI-Paβflap, α vs. α-AlpA: p = 0.00011. λCI-Ecβflap, α vs. α-AlpA: p = 6.5 × 10−6. λCI-Ecσ70 (1–56), α vs. α-AlpA: p = 1.4 × 10−10. λCI-Ecσ70 (1–93), α vs. α-AlpA: p = 2.3 × 10−5. λCI-Paσ70 (1–58), α vs. α-AlpA: p = 0.0002. p-Values indicated by the following symbols: ≤0.001 = ***, ≤0.0001 = ****. Source data are provided as a Source Data file.
