Transcription initiation: promoters, general factors and polymerase recruitment · seed 1 · A4, ink-friendly. The answer key prints on its own page for grown-ups.

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Science · Biochemistry & Molecular Biology · ages 19-21
Name ______________________   Date ____________

  1. RNA polymerase II alone is sufficient for normal promoter-specific initiation.

    Circle one:   True   False

  2. In the model TATA-promoter pathway, which interaction begins assembly?

    • TBP within TFIID binds TATA
    • TFIIH opens DNA before TFIID binds
    • Polymerase II recognises TATA without general factors

  3. Which activities does TFIIH contribute to polymerase II initiation?

    • RNA cleavage and CTD dephosphorylation
    • TATA recognition and RNA polyadenylation
    • Promoter opening and CTD phosphorylation

  4. Which mechanism describes an activator increasing initiation?

    • Stabilising promoter assembly
    • Increasing translation of existing messages
    • Slowing decay of already completed messages

  5. A cell no longer needs new RNA from a gene. What can reducing initiation achieve directly?

    • Faster removal of the gene's existing mRNAs
    • Fewer unnecessary RNA chains started
    • Reduced translation of each existing mRNA

  6. Which statement correctly contrasts bacterial initiation with polymerase II initiation?

    • Bacterial sigma performs the same assembly pathway as TFIID
    • Polymerase II uses sigma to recognise minus 10 elements
    • Sigma helps bacterial core polymerase recognise promoters

  7. TFIIH kinase activity is lost. Which conclusion is justified before measuring RNA production?

    • Productive transcription may be impaired
    • Polymerase recruitment must be completely abolished
    • Promoter opening must increase to compensate for the lost kinase

  8. Kim says a promoter-proximal pause necessarily ends that RNA chain. Which correction fits regulated pausing?

    • Pausing and termination release the same RNA product
    • Pause release can let the existing chain continue
    • Pausing changes recruitment but not elongation of that chain
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Answer key

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Assemble first, then read W1-mt_0Ky-pYgh0Y-s1

  1. False · General transcription factors help polymerase II assemble and initiate at a promoter.
  2. TBP within TFIID binds TATA · TBP within TFIID binds TATA at the start of this model pathway. Other promoter assembly pathways can differ.
  3. Promoter opening and CTD phosphorylation · TFIIH contributes ATP-driven promoter opening and kinase activity that phosphorylates the CTD.
  4. Stabilising promoter assembly · Stabilising initiation machinery can increase initiation. Translation and mRNA decay act at later expression stages.
  5. Fewer unnecessary RNA chains started · Initiation starts RNA chains. Reducing it limits new starts, without directly removing or changing translation of existing messages.
  6. Sigma helps bacterial core polymerase recognise promoters · Sigma assists bacterial promoter recognition. Polymerase II uses its general transcription factors instead.
  7. Productive transcription may be impaired · The kinase supports CTD phosphorylation and initiation transitions. Its loss does not establish a complete block or a compensating increase.
  8. Pause release can let the existing chain continue · A pause can be reversible. Release can allow the existing polymerase and RNA chain to continue elongation.
Worksheet · LightMySky