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Multiple Choice
Which subunit of the E. coli RNA polymerase confers specificity to transcription?
A
Alpha (α) subunit
B
Beta (β) subunit
C
Omega (ω) subunit
D
Sigma (σ) factor
Verified step by step guidance
1
Understand the role of RNA polymerase in transcription: RNA polymerase is an enzyme responsible for synthesizing RNA from a DNA template during transcription.
Identify the components of E. coli RNA polymerase: The core enzyme consists of multiple subunits, including alpha (α), beta (β), and omega (ω), but lacks specificity for promoter recognition.
Learn about the sigma (σ) factor: The sigma factor is a protein that associates with the core RNA polymerase enzyme to form the holoenzyme, which is capable of specific promoter recognition.
Recognize the function of the sigma (σ) factor: The sigma factor confers specificity to transcription by guiding the RNA polymerase to specific promoter regions on the DNA, initiating transcription at the correct site.
Conclude the importance of the sigma (σ) factor: Without the sigma factor, the RNA polymerase core enzyme cannot efficiently recognize and bind to promoters, highlighting the sigma factor's crucial role in transcription specificity.