RNA Flashcards
Which 2 processes form the central dogma?
Transcription and translation
What are the 3 main classes of RNA?
ribosomal RNA
transfer RNA
messenger RNA
Which 4 bases make up RNA?
Adenine
Cytosine
Guanine
Uracil
Which unusual pyrimidine is found in the DHU loop of tRNA?
Dihydrouracil
What are the 4 stem-loops of tRNA?
Anticodon loop
DHU loop
TψC loop
Amino acid binding site
Which polymerase synthesises all mRNA?
Polymerase II
What are the 3 main types of polymerase found in eukaryotes?
Pol I, Pol II, Pol III
How can polymerases be distinguished?
By their sensitivity to toxins such as α-amanitin (which is derived from a fungus)
What base sequence is important for the binding of Pol II in the promoter region?
TATAT, found around 25 nucleotides before the initiation site for transcription
In which transcription factor is the TATA box binding protein found?
TF(II)D
What are the 2 types of transcription factor?
General
Specific
What is the function of TF(II)D?
It puts a kink in the DNA, determining the transcriptional start and direction of transcription. It also provides a landing platform for further transcription factors and for RNA polymerase
What are the 2 strands during transcription?
Coding strand - Not being copied
Template strand - Being copied
What sequence of bases releases RNA and dissociates polymerase?
A stretch of Us
What type of transcription factor is required specific regulation?
Specific transcription factors
What 2 DNA binding proteins are required for regulation?
An activator protein and a regulatory protein
What are the stages of coordinated gene expression?
A stress causes expression of a gene that codes for regulatory proteins.
These regulatory proteins then promote expression of a number of other genes that can respond to the stress
What are the 3 binding regions of steroid receptors (transcription factors)?
Transactivation domain
DNA-binding domain
Ligand binding domain
What substance binding causes the transcription factor to move to the nucleus?
A ligand (The steroid)
Where on DNA do steroid receptors bind?
Steroid-response elements
What is found at the ends of an mRNA strand?
A GTP cap on the 5’ end, and a poly A tail on the other end
