Given a context passage, generate a question from the passage such that its answer is shortest continous span from the passage.

Q: The Bacillus anthracis toxin genes, cya, lef, and pag, can be viewed as a regulon, in which transcription of all three genes is activated in trans by the same regulatory gene, atxA, in response to the same signal, CO2. In atxA+ strains, toxin gene expression is increased 5- to 20-fold in cells grown in 5% CO2 relative to cells grown in air. CO2-enhanced toxin gene transcription is not observed in atx4-null mutants. Here, we used two independent techniques to obtain evidence for additional CO2-induced atxA-regulated genes. First, total protein preparations from atxA4+ and atxA isolates grown in 5% CO2 and in air were examined by two-dimensional electrophoresis. Comparison of the resulting protein patterns indicated that synthesis of non-toxin proteins is influenced by growth in elevated CO2 and the toxin gene regulator, atxA. Second, we generated random transcriptional lacZ fusions in B. anthracis with transposon Tn917-LTV3. Transposon-insertion libraries were screened for mutants expressing CO2-enhanced atxA-dependent beta-galactosidase activity. DNA sequence analysis of transposon insertion sites in 17 mutants carrying CO2- and atxA-regulated fusions revealed 10 mutants carrying independent insertions on the 185-kb toxin plasmid pXO1 which did not map to the toxin genes. The tcr-lacZ fusion mutants (tcr for toxin coregulated) were Tox+, indicating that these genes may not be involved in anthrax toxin gene activation. Our data indicate a clear association of atxA with CO2-enhanced gene expression in B. anthracis and provide evidence that atxA regulates genes other than the structural genes for the anthrax toxin proteins.

A: Which metabolite activates AtxA?
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Q: Menpehtyre Ramesses I (traditional English: Ramesses or Ramses) was the founding pharaoh of ancient Egypt's 19th dynasty.

A: What is the position of Ramesses I?
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Q: In the published version of The Silmarillion, Orodreth (IPA: (orodre)) was an Elf of the First Age, the second son of Finarfin (with Finrod Felagund, Angrod, Aegnor, and Galadriel being his siblings), and a ruler of Nargothrond.

A:
Who is Orodreth's sister?
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