Gene Organisation and Transcription-1 Flashcards
Define Transcription
The process in which nucleotide information in the DNA is copied into RNA is called TRANSCRIPTION
What does RNA Polymerse 1 do?
Transcribes rRNA genes
What does RNA polymerase 2 do?
Transcribes genes encoding proteins into mRNA
What does RNA polymerase 3 do?
Transcribes tRNA and 5S RNA genes
Define Gene Promotor
The DNA sequences at which the initiation complex assembles is called a gene promoter .
What are transcription factors
The amount (level) of transcription from a given gene is regulated by the activity of DNA binding proteins known as Transcription Factors.
Name the parts that make Gene promoter
TATA Box Transcription Binding Site add pic
List the components of the Basal Transcription Complex
DAB JHEF
TFIID TFIIA TFIIB TFIIJ TFIIE TFIIF TFIIH
These are known as basal transcription factors RNA POL II add pic.
What is the role of the Basal Transcription factor
The Basal Transcription Complex allows RNA polymerase II to be phosphorylated and then engage in transcription
What does TF IID contains
contains TATA Binding Protein(TBP) and TBP Accessory Factors (TAF’s).
What Does TF IID do when it binds to DNA
Partially unwinds the DNA helix, widening the minor grove to allow extensive contact with bases within the DNA
Why is TF IIB particularly important?
. TFIIB is particularly important, as it is able to bind to TFIID and RNA Polymerase II
What is already bonds to RNA polymerase II
TF IIF
List the order that transcription factors bind to TATA box
D A and B RNA POL II with TF IIF J and E and H
What doe TF IIH do?
TFII H promotes further unwinding of the DNA helix to facilitate RNA synthesis by RNA Polymerase II.
What do transcription factors do when they bind to DNA?
Transcription factors “bend DNA” on binding. They can interact with each other and the Basal Transcription Complex to modulate transcription.
Transcription factors also facilitate transcription by helping to remodel “chromatin”. They do this by recruiting proteins with enzymatic activities that modify histones. How do they modify histones?
add pic
