Gene therapy - carla - lectures 2,3 &5

What is gene expression?

Conversion of DNA information into a functional product

Which molecule is responsible for synthesizing RNA from DNA?

RNA polymerase

What is the central dogma of molecular biology?

DNA → RNA → Protein

Which mutation causes sickle cell anaemia?

Substitution of glutamic acid with valine

What is the consensus sequence at the -10 region of prokaryotic promoters?

TATAAT

Which RNA type codes for proteins?

mRNA

What is the function of tRNA?

Adapts mRNA to amino acids during translation

What is the role of introns in eukaryotic genes?

Regulate splicing and transcription

Which RNA type adds peptide tags to misfolded proteins?

tmRNA

What is the TATA box?

A promoter element in eukaryotes

What happens during RNA processing in eukaryotes?

Introns are removed and exons spliced

What is the function of enhancers in gene expression?

Modulate transcription rate

What is the role of transcription factors in eukaryotes?

Assist RNA polymerase in initiating transcription

Which transcription factor type interacts with silencers to repress transcription?

General transcription factors

What allows distant transcription factor binding sites to influence transcription?

DNA looping

What are DNA-binding proteins (DBPs) involved in?

Chromatin structure and gene expression regulation

Which groove of DNA is commonly involved in sequence-specific protein interactions?

Major groove

Which DNA-binding protein initiates transcription by binding to the TATA box?

TATA-binding protein

What is the recognition helix in the HTH motif responsible for?

Binding the major groove of DNA

What type of gene regulation is the tryptophan operon an example of?

Negative control

What stabilizes the structure of zinc finger motifs?

Zinc ion

What is the most common DNA-binding domain in eukaryotes?

Cys2His2 zinc finger

What does the β-sheet in the Cys2His2 zinc finger help determine?

Positioning of the α-helix in the major groove

What is the function of the leucine zipper motif?

Dimerization of proteins via hydrophobic interactions

Which DNA-binding motif uses a β-sheet to bind the minor groove?

TBP domain

What lab technique is used to locate protein-binding sites on DNA?

Gel mobility shift assay

Which RNA polymerase transcribes mRNA?

RNA Pol II

What does RNA polymerase I transcribe?

18S, 25S, and 5.8S rRNAs

Which RNA polymerase transcribes tRNA and 5S rRNA?

RNA Pol III

What is the role of general transcription factors (GTFs)?

Assist RNA Pol II in transcription initiation

Which GTF binds first to the TATA box?

TFIID

What is the TATA box?

A conserved promoter element

What is the function of TFIIH?

DNA unwinding and phosphorylation of RNAP II

What is the CTD of RNA polymerase II?

The C-terminal domain with repeated amino acid sequences

What do activators bind to in eukaryotic transcription?

Enhancers

What do repressors bind to in eukaryotic transcription?

Silencers

Which transcription factor is involved in 5S rRNA transcription by RNAP III?

TFIIIA

Which transcription factor is involved in tRNA transcription by RNAP III?

TFIIIC

What is the role of UBF and SL1 in RNAP I transcription?

Recruitment of RNAP I to the promoter

What is the function of histone acetylation in transcription?

Increased accessibility for transcription

What is the function of the CTD of RNA Polymerase II?

Binding site for mRNA processing enzymes

Which RNA polymerases lack a CTD?

RNA Pol I and III

What modification occurs at the 5’ end of eukaryotic mRNA?

Capping with methylated guanine

Which enzyme adds GMP in reverse linkage during capping?

Guanyl transferase

What is the consensus sequence for polyadenylation?

AAUAAA

Which proteins are involved in polyadenylation?

CPSF and CstF

What is the role of Poly-A Polymerase (PAP)?

Adds adenine nucleotides to the 3’ end of mRNA

What is the purpose of capping and polyadenylation?

Increase mRNA stability and facilitate export

What are the first and last two nucleotides of most introns?

GU and AG

What is the branch point nucleotide involved in splicing?

Adenine

What structure is formed during the first step of splicing?

Lariat

Which snRNAs are involved in splicing?

U1, U2, U4, U5, U6

What is the spliceosome composed of?

snRNPs and accessory proteins

What is the role of Sm proteins in snRNPs?

Form the core of snRNPs and bind snRNAs

What is alternative splicing?

Joining exons in different combinations