Transcription
Bacteria Transcription
Eukaryotic Transcription
RNA + RNA Processing
Misc.
100
What is the starting material and the product of transcription?
DNA --> RNA
100
What are the important promoter consensus sequences?
-35 consensus
PRIBNOW box (-10 consensus)
100
What are the important promoter consensus sequences? Which promoter are they a part of?
TFIIB (-35 consensus sequence)
TATA box (-25 consensus sequence)
these are part of the core promoter
100
What does colinearity mean?
the number of nucleotides in a gene is proportional to the number of amino acids produced
100
What is the central dogma?
Genetic information flows in one direction
DNA --> RNA --> protein
200
Where does transcription happen?
Bacteria: cytoplasm
Eukaryotes: nucleus
200
How do rRNA and tRNA genes appear in bacteria?
they are polycistronic; one promoter synthesizes a long RNA strand with rRNA and tRNA
200
How do rRNA genes appear in Eukaryotes?
they are polycistronic
one promoter synthesizes multiple rRNAs
200
What are the steps of pre-mRNA processing? When does each occur?
Addition of 5' cap (co-transcriptional)
3' cleavage and addition of poly (A) tail (post transcriptional)
RNA splicing (post-transcriptional)
200
What ingredients are involved in transcription?
-template DNA
-RNA polymerase
-transcription factors
-RNA nucleotides
-RNA
300
What are the parts of a transcription unit? Which sequences are transcribed in the mRNA?
promoter, coding region, terminator
transcribed: coding region and terminator
300
What makes up the RNA polymerase in bacteria?
Holoenzyme = core enzyme + sigma factor
300
How does termination occur in eukaryotes?
-RNA polymerase transcribes past the coding sequence
-The 3' coding region of the RNA is cleaved
-Rat1 exonuclease attaches to the 5' end of the RNA still attached to the DNA
-Rat1 moves toward RNA polymerase and degraded the RNA as it goes
-Rat1 reaches RNA polymerase and transcription is terminated
300
Name three types of RNA that need to be processed.
pre-mRNA
tRNA
rRNA
300
How does tRNA get modified?
introns are removed, bases are added to the 3', some bases are modified
400
What is the difference between a eukaryotic transcription unit vs. bacteria transcription unit?
eukaryotes: one gene
bacteria: multiple genes in one transcription unit
400
How does rho-dependent termination occur in bacteria?
-Rho binds to the rut site and moves toward the 3' end of the RNA
-RNA polymerase pauses when it hits the terminator sequence
-Rho catches up and uses its helicase activity to unwind the RNA from the DNA
400
Why are the two promoters important?
core promoter: where the basal transcription apparatus binds
regulatory promoter: where transcription factors bind to interact with the transcription apparatus and impact the rate of transcription
400
What is the function of mRNA, tRNA, rRNA, and snRNA?
mRNA: encode a protein
tRNA: adaptor between mRNA and amino acids
rRNA: form the ribosome
snRNA: splicing and other processes
400
What are the important genes in the large and small subunit for bacteria?
Small: 16S
Large: 23S and 5S
500
What determines which strand of DNA will be the template vs. the non-template?
the promoter
500
How does rho-independent termination occur?
-the RNA transcript contains inverted repeats followed by a strand of uracils
-the strings of uracils cause RNA polymerase to pause
-the inverted repeats cause RNA to form a hairpin structure
-the DNA-RNA hybrid is destabilized and the RNA transcript is able to separate
500
What binds to the TATA box?
TFIID (transcription factor) binds to the TATA box on the core promoter due to the TATA-binding protein (TBP) which recognizes the box
500
How does splicing occur?
-the 5' end of the intron is cleaved from the upstream exon and attached to the branch point to form a lariat
-the 3' end of the intron is cleaved from the downstream exon and the ends of the exons are spliced together 
500
What are the important genes in the small and large subunits for Eukaryotes?
Small: 18S
Large: 28S, 5.8S, 5S