Nucleic Acids Biochemistry and Promoter Sequences Quiz

Eukaryotic promoters contain subsets of four different sequences and use many eukaryotic GTFs, while prokaryotic promoters are recognized by a σ factor and assist RNA Pol.

TATA-binding protein (TBP) bends the DNA minor groove flat with a β-sheet to assist in RNA Pol II recruitment and chromatin unwinding for transcription initiation.

Elongation factor proteins accelerate RNA growth by stopping pauses and errors during transcriptional elongation.

<p>RNA is capped early to protect the transcript and ensure proper processing, involving GTP, SAdoMet, and three sequential enzymes.</p> Signup and view all the answers

<p>Multisubunit Mediator complexes are generally needed for RNA Pol activity and serve as a bridge between transcription factors and RNA Pol II.</p> Signup and view all the answers

<p>sRNAs in bacteria can serve to repress levels of one protein and promote another. They regulate gene expression by binding to complementary target mRNAs to form double-stranded RNAs, causing mRNA destruction by RNase and blocking translation. sRNAs can also stimulate translation in some cases.</p> Signup and view all the answers

<p>During stationary phase in bacteria, the alternative σ S factor is made and outcompetes the σ 70 subunit. This promotes the transcription of survival proteins. σ S factor translation is affected by mRNA-sRNA binding, either stimulated or inhibited.</p> Signup and view all the answers

<p>Hfq, a RNA chaperone protein, helps sRNA bind to mRNA target. It aids in the binding of short, imperfect matching mRNA-sRNA and stabilizes it. Additionally, Hfq can activate translation by binding and removing a RBS-blocking RNA region.</p> Signup and view all the answers

<p>Riboswitches are gene transcripts that directly sense metabolite concentration changes. They act as &quot;built-in&quot; metabolite sensors using RNA sequences to control gene expression. Riboswitches can alter their secondary structure in response to metabolite binding, thereby influencing gene expression.</p> Signup and view all the answers

<p>Regulatory RNAs in bacteria alter RNA structure, recruit proteins, and can enzymatically alter to 'mature' RNAs. They also bind proteins and metabolites to alter metabolism, regulate gene expression, and control transcription through mechanisms such as sRNA-mRNA binding, ribosome blocking, and mRNA destruction.</p> Signup and view all the answers