This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Biochemistry
[{'content': 'The sigma (σ) subunit of prokaryotic RNA polymerase \nSelect and explain. \nA. Binds the antibiotic rifampicin, B. Is inhibited by α-amanitin, C. Specifically recognizes the promoter site, D. Is part of the core enzyme', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Sigma (σ) factor recognizes promotor sequences on the DNA template. Different factors recognize a different group of genes.\nα-amanitin inhibit RNA polymerase II of eukaryotes.\nRifampicin inhibits β-subunit of RNA polymerase.\nSigma unit is not a part of core enzyme; it is a part of holoenzyme.\n\nRNA polymerase (holoenzyme) = core enzyme (2α, β,( β’) + sigma (σ) subunit', 'role': 'assistant'}]