Match the following (most appropriate combinations): Alpha-amanitin Sigma 70 Sigma 54 -35 Box/sequence Holoenzyme Inhibits pol II transcription ✓ [Choose ] Used for transcription of genes that respond to nitrogen starvation (nitrogen uptake and metabolism) Used for transcription of most (housekeeping) bacterial genes Inhibits pol Il transcription Core RNA polymerase associated with sigma Bacterial promoter element [Choose ]

The DNA sequence of the promoter region of E. coli xyzA gene is shown below. Transcription start site is the A (in bold) at position 43.              5          10        15         20        25         30         35        40          45         50 GAGCT GTTGA CAATT AATCA TCGAA CTAGT TAACT AGTAC GCAAG TTCAC Mutations were introduced in the sequence to identify residues important for gene expression. Indicate the effect of the following mutations on xyzA expression (increase, decrease, no effect, cannot be predicted). Provide reasoning for each answer. A. G3A (G at position 3 was changed to A) G9A Deletion of TCA at position 18-20 C22A T31A, A32T double mutant T35G G45C C48A B. What are the promoter sequences of the gene?

In bacteria, a transcription experiment in vitro with purified RNA polymerase holoenzyme is fairly straightforward. In eukaryotes, it is not. Explain this observation, including what would be meant by the term “holoenzyme” for a eukaryotic RNA polymerase.

Match the regulatory RNA to each of the following descriptions. Regulatory RNA that prevents transcription by recruiting DNMT enzymes Regulatory RNA that prevents translation by acting either in cis- or trans- but not by binding RISC Regulatory RNA found only in eukaryotes that is not perfectly complementary to the target RNA [Choose ] [Choose ] [Choose ] antisense RNA siRNA IncRNA miRNA riboswitch <