module 7 lec 11 Flashcards
What does RNA polymerase I transcribe?
Most rRNAs (ribosomal RNAs).
What does RNA polymerase II transcribe?
mRNA and microRNAs.
What does RNA polymerase III transcribe?
tRNA, 5S rRNA, and small RNAs (including small nuclear RNAs)
What is a cis factor in transcription?
A cis factor is a DNA sequence, such as a promoter or enhancer, that regulates transcription of nearby genes.
What is the function of a promoter in transcription?
The promoter is a DNA sequence that signals the start of transcription and where RNA polymerase binds.
What is the TATA box?
The TATA box is a conserved DNA sequence (usually around -30) that helps in the binding of RNA polymerase II for transcription initiation.
What is the basal level of transcription?
The basal level of transcription is the basic level of gene expression without any regulatory influences, often mediated by the promoter.
What are enhancers in transcription regulation?
Enhancers are DNA sequences that increase transcription levels, and they can function at varied distances and orientations relative to the gene.
What are insulators in gene regulation?
Insulators are DNA sequences that block the interaction between enhancers and promoters, preventing inappropriate gene activation.
How do insulators control enhancer/promoter interactions?
Insulators physically separate enhancers from promoters, ensuring that enhancers only activate the correct target genes.
How do insulators influence DNA organization?
Insulators help organize the genome by forming loops in DNA, preventing enhancers from activating genes outside the designated region.
What is the role of insulators in chromatin architecture?
Insulators act as barriers to prevent the spread of activating or silencing signals across chromatin regions, maintaining proper gene expression.
What are trans factors in transcription regulation?
Trans factors are proteins that bind to the promoter or enhancer regions of DNA to help regulate transcription initiation.
What is the role of basal factors in transcription?
Basal factors are proteins that bind to the promoter region and are necessary for RNA polymerase to initiate transcription.
What is the function of TATA box-binding protein (TBP)?
TBP binds to the TATA box in the promoter region, initiating the assembly of the transcription machinery
What are TAFs and how do they assist in transcription initiation?
TAFs (TBP-associated factors) are proteins that interact with TBP to help RNA polymerase II bind to the promoter.
How do TBP and TAFs assist RNA polymerase II in transcription initiation?
TBP and TAFs recruit RNA polymerase II to the promoter, facilitating the start of transcription.
