RNA Metabolism

What is the fundamental chemical mechanism for the elongation of an RNA strand by RNA polymerase?

During active transcription in E. coli, what is the approximate length of the unwound DNA region, known as the transcription bubble, maintained by the RNA polymerase?

In the E. coli RNA polymerase holoenzyme, which subunit is responsible for promoter recognition and directs the enzyme to specific binding sites on the DNA?

Which of the following is the consensus sequence for the -10 region (Pribnow box) of promoters recognized by E. coli RNA polymerase containing sigma-70?

Actinomycin D is an antibiotic that inhibits transcription. What is its mechanism of action?

What is the primary function of the 5' cap structure found on eukaryotic mRNAs?

What is the key nucleophile that initiates the first transesterification step in the splicing of group II introns?

What is the function of the enzyme Drosha in miRNA processing?

What is the primary product of the action of reverse transcriptase on a viral RNA template?

What is the role of the enzyme telomerase?

The RNA polymerase from the mushroom Amanita phalloides is insensitive to the toxin alpha-amanitin, which it produces. Which eukaryotic RNA polymerases in animal cells are blocked by alpha-amanitin?

What is the primary role of the small nucleolar RNAs (snoRNAs) in eukaryotes?

Retroviruses such as HIV contain an enzyme that catalyzes three distinct reactions. Which of the following is NOT one of these reactions?

Which class of introns is characterized by its removal within a large protein complex called a spliceosome, which is composed of small nuclear ribonucleoproteins (snRNPs)?

What is the function of the enzyme polynucleotide phosphorylase, which was discovered before DNA polymerase?

The error rate for transcription is approximately one error for every 10,000 to 100,000 ribonucleotides incorporated. Why is this higher error rate tolerated in the cell compared to the much lower error rate of DNA replication?

What is the role of the U1 snRNP in the splicing of spliceosomal introns?

The human immunodeficiency virus (HIV) is a retrovirus. What is the error rate of its reverse transcriptase during replication?

A newly synthesized RNA molecule is referred to as what?

Which enzyme is responsible for removing the RNA primers of Okazaki fragments and replacing them with DNA in E. coli?

In the process of polyadenylation of eukaryotic mRNAs, the highly conserved sequence (5')AAUAAA(3') serves as a signal for what event?

The splicing of group I and group II introns involves two sequential transesterification reactions. What does this mechanism ensure?

What type of enzyme is the bacterial RNase P, which processes the 5' end of tRNAs?

What is the function of retrotransposons, such as the Ty element in yeast?

During the elongation phase of transcription in E. coli, the protein NusA binds to the RNA polymerase. What is the effect of NusA binding?

What is the approximate size of the mature microRNAs (miRNAs) after all processing steps are complete?

What is the function of the enzyme Dicer in RNA interference pathways?

In the SELEX method for generating RNA polymers with new functions, what is the practical limit for the complexity of an initial RNA mixture?

What is the function of the carboxyl-terminal domain (CTD) of the largest subunit of eukaryotic RNA polymerase II?

The rho-dependent transcription terminators in E. coli are characterized by what feature in the RNA transcript?

What is the primary function of RNA polymerase I in eukaryotes?

The alternative processing of the calcitonin gene transcript in rats leads to the production of two different hormones in different tissues. What are these two hormones?

What is the source of the methyl groups used to form the 5' cap on eukaryotic mRNAs?

What are the conserved dinucleotide sequences typically found at the 5' and 3' ends of spliceosomal introns?

In the SELEX process, after RNA polymers that bind to a target are collected, what is the next step to amplify these selected sequences?