Deck 24: Transcription and Post-Transcriptional Processing

Question 1

Rho-dependent termination of transcription makes use of a hexameric protein, which has RNA-DNA helicase activity.

Answer 1

True

Question 2

Eukaryotic transcription normally takes place on a chromatin template at nuclease-accessible sites.

Answer 2

True

Question 3

Which of the following statements is FALSE?

A) RNA polymerase II is responsible for the transcription of genes encoding protein-coding sequences only.
B) Many promoters recognized by RNA polymerase II contain regulatory elements several kbp upstream of the initiation site.
C) TFIIB has a role in converting a closed-promoter into an open-promoter complex.
D) The C-terminal domain of the largest subunit of RNA pol II undergoes extensive phosphorylation prior to transcription elongation.
E) A multiprotein complex is involved in communication between upstream control elements and proteins bound at the promoter.

Answer 3

A

Question 4

In bacteria, mRNA, tRNA and rRNA are all transcribed by the same RNA polymerase.

Question 5

Most ________ of transcription in prokaryotes is based on a weakened interaction due to ________ base pairing between the template and the transcript as well as a stable stem loop structure in the nascent transcript which eliminates base pairing between the template and transcript upstream of the AU interaction.

Question 6

In eukaryotes RNA polymerase I transcribes all of the ribosomal RNA components.

Question 7

Which of the following is FALSE when comparing DNA pol III and RNA polymerase?

A) There are many more copies of RNA polymerase in the cell.
B) DNA pol III is much more processive.
C) RNA polymerase makes more errors.
D) RNA polymerase has a much slower kcat.
E) RNA polymerase does not need a primer.

Question 8

All the tRNA genes are transcribed by ________ in eukaryotes.

Question 9

Which of the following statements about E. coli RNA polymerase is INCORRECT?

A) It has five different subunits.
B) The σ subunit can be dissociated easily from the rest of the enzyme.
C) The σ subunit is responsible for accurate determination of transcription start sites.
D) Without the σ subunit the enzyme has no RNA polymerase activity.
E) The σ subunit has a role in regulation of transcription.

Question 10

Degradation of bacterial mRNAs occurs:

A) from the 3' end.
B) largely by the activity of non-specific nucleases.
C) from the 5' end.
D) relatively slowly.
E) from both 3' and 5' ends at the same time.

Question 11

After promoter clearance by RNA polymerase II:

A) all associated factors remain bound to the polymerase for elongation.
B) a subset of factors remain at the promoter region.
C) no further elongation factors are acquired by the polymerase.
D) no further chromatin remodeling is required.
E) transcription continues until the polymerase reaches the poly (A) tail.

Question 12

High levels of histone ________ correlate with high levels of transcriptional activity.

Question 13

RNA polymerase transcribes all DNA sequences at an equal rate.

Question 14

In eukaryotes a set of ________ function in a comparable manner to the σ subunit of E. coli RNA polymerase.

Question 15

Alignment of conserved sequences in promoters recognized by E. coli RNA polymerase revealed two ________ sequences upstream of the transcribed region, which are separated by similar lengths of DNA.

Question 16

In bacteria post-transcriptional processing of pre-rRNA species can yield mature tRNAs.

Question 17

Which of the following types of post-transcriptional processing does NOT occur for bacterial tRNAs?

A) Exonuclease cleavage
B) Endonuclease cleavage
C) Non-template directed addition of bases
D) Methylation of bases
E) Addition of a phosphate group to the 5' end

Question 18

In eukaryotes genes encoding enzymes for metabolic pathways often exist as operons of several genes with a single regulatory region to provide coordinate regulation of all genes required for the pathway.

Question 19

Which of the following is NOT correct when considering the initiation of transcription in E. coli?

A) The σ subunit of RNA polymerase makes strong contacts with the -10 region of promoters.
B) Only the -10 region of the promoter is required.
C) DNA melting near the transcription start site is essential for promoter recognition.
D) The phosphodiester bonds that are formed are not stable until about 10 nucleotides have been incorporated.
E) The RNA polymerase contacts about 50 bp of DNA.

Question 20

The different sensitivities to the toxin ________ revealed that eukaryotes have three distinct RNA polymerases for synthesis of mRNA, rRNA and small RNAs including tRNA and the 5S species of rRNA.

Question 21

Splicing of mRNA occurs in spliceosomes and chemically is a series of ________ reactions.

Question 22

DNA microarrays can be used for gene ________ profiling, starting with RNA and using the enzyme ________ to synthesize cDNA and simultaneously incorporate nucleotides labeled with fluorescent dyes.

Question 23

Alternative splicing can:

A) be tissue-specific.
B) produce proteins with different functions from the same gene.
C) contribute to temporal control of gene expression.
D) produce mRNAs that are nonfunctional.
E) all of the above.

Question 24

Which of the following is the first step in chromatin immunoprecipitation?

A) Extraction of chromatin from cells
B) Cross-linking with formaldehyde
C) Shearing by sonication
D) Addition of antibodies to recognize proteins that bind to DNA
E) PCR to amplify the target sites

Question 25

All processing of eukaryotic mRNAs takes place in the nucleus after transcription has been completed.

Question 26

The 5' cap added to eukaryotic mRNA serves to stabilize the mRNA and assists in the efficiency of ________.