Question | Answer |
mRNA precursors may be spliced by | spliceosome |
RNA synthesis (RNA, mRNA, and rRNA) is called | transcription |
Sequences found on the same molecule of DNA that contain information such as promoter sites are called | cis-acting sequences |
Activator and repressor proteins that participate in gene regulation are called | Transacting elements |
Unlike DNA synthesis, RNA synthesis does not require a | primer |
The region of RNA synthesis containing the DNA, RNA, and enzymes is called the | transcription bubble |
______ The term used to describe the mechanism by which drugs and other molecules slip between the bases of the DNA helix. | Intercalation |
A change made to the base sequence of RNA following transcription is called | RNA editing |
_____ A mechanism of splicing that allows diversity in the proteins generated from a particular gene. | Alternative splicing |
An RNA molecule that is catalytic is called a | ribozyne |
At least _____ % of all genetic diseases are caused by mutations that affect RNA splicing. | 15 |
There are approximately _____ promoter sites found in E. coli. | 2000 |
The ______ sequence is determined by an alignment of DNA base sequences used to deduce a recurring pattern or motif. | consensus |
The coding strand has the ____ sequence as the RNA transcript (except T instead of U) | same |
The ___ subunit of RNA polymerase recognizes promoters during heat-shock conditions. | o-32 |
The RNA polymerase can unwind approximately _____ bases, or about 1.6 turns of B-DNA. | 17 |
The rate of RNA synthesis in E. coli is approximately ______ nucleotides per minute. | 50 |
The Rho protein terminates transcription by acting as a ______ | helicase |
The enzyme _____ transcribes a single precursor that encodes for the 18S rRNA, the 28S rRNA, and the 5.8S rRNA. | RNA polymerase I |
RNA self-splicing demonstrates the role of RNA as a ______ | Catalyst |
Percentage of diseases caused by mutations that affect mRNA splicing | 15 |
Functions of RNA polymerase include | searching for promoter sites, unwinding short stretches of DNA, detecting termination signals |
DNA footprinting is a technique that allows one to determine | where proteins bind to DNA |
The structure of DNA must be in the _____ for transcription to occur. | open promoter complex |
RNA modifications in prokaryotes includes the following: | cleavage and modification of nascent RNA, addition of nucleotides |
Actinomycin interferes with transcription by | binding to the DNA helix and preventing its use as an RNA template |
RNA polymerase I transcribes the genes for | 18S, 5.8 S, and 28S rRNA |
Many eukaryotic promoters contain the following significant sites: | a TATA site near -30 to -100, a CAAT site near -40 to -150 |
The key event in eukaryotic transcriptional activation is | binding of the TATA-box-binding protein (TBP) to the TATA box |
Which of the following modifications are made to eukaryotic tRNA transcripts? | modification of base and ribose moieties, removal of 3' trailer, cleavage of 5' leader by RNase P, CCA is added |
The chemical reaction(s) in RNA splicing include | two transesterifications |
The carboxyl-terminal domain (CTD) of RNA polymerase II is involved in | recognition of the termination signal |
Diseases caused by mutations in pre-mRNA or in the splicing factors include | Retinitis pigmentosa |
Proteins that possess alternative splicing products include | calcitonin |
The role of GTP in self-splicing is | as a cofactor |
Name the three stages of RNA synthesis | The three stages of RNA synthesis are initiation, elongation, and termination |
What is the definition of a promoter? | A promoter is a sequence of DNA that directs the RNA polymerase to the proper site for transcription initiation |
What is the significance of the o- subunit? | The o- subunit contributes to initiation in several ways. It allows RNA polymerase to recognize promoter sites, & decreases nonspecific DNA to RNA polymerase interaction by decreasing the binding affinity of nonspecific interactions |
How does RNA polymerase find the proper binding site? | The RNA polymerase binds to the DNA and slides along it until the proper site is found |
What is the theory for how palindromic RNA polymerase transcription termination signals function? | In the palindromic region the bases form a hairpin stem and loop structure that is followed by a series of U-A base pairs. It is theorized that the RNA polymerase stalls at the palindromic sequence, & DNA template separates from nascent RNA at this point |
What is a common feature of both protein-dependent and protein-independent termination signals in transcription? | The signals that mediate termination events appear to function in the newly synthesized RNA, and not in the template DNA |
How does the antibiotic rifamycin function mechanistically? | Rifamycin functions by interfering with RNA synthesis initiation. The antibiotic binds to a channel required by the RNA-DNA complex, interfering with the formation of the initial phosphodiester bonds |
How does binding of heat-shock proteins differ between E. coli and Drosophila? | Heat-shock transcription factor (HSTF) I Drosophila differs from o-32, E. coli, in binding directly to response elements in heat-shock promoters rather than first becoming associated with RNA polymerase |
Where are enhancer sequences found in the gene? | Enhancers can be found upstream, downstream, or in the middle of a transcribed gene. They are often located thousands of bases away from the transcriptional start site. |
Approximately, how many mRNA transcripts in higher eukaryotes undergo processing? | Nearly all mRNA precursors in higher eukaryotes are spliced |
What is unique about the type of RNA editing that occurs in the transcript for Apolipoprotein B? | The nucleotide sequence of mRNA is changed AFTER its synthesis. A specific cytidine residue of mRNA is dreaminated to uridine, which changes an amino acid from Gln to stop |
What is present in the spliceosome complex? | The spliceosome complex contains the snRNPs, splicing factor proteins, and the mRNA molecule |
Draw the mechanism of lariat formation in a splicing pathway | Several comparisons are shown in figure 29.40 |
What are the two types of splicing categories? | The reactions are grouped in categories of Group I and Group II. Group I uses a guanosine cofactor, whereas Group II utilizes the 2' OH group of an intron adenylate |