Transcription, RNA syntesis and Pre mRNA Processing Flashcards
What genes make up the lac operon and what do they code for
LacZ= β-galactosidase
LacY= lactose permease
LacA=transacetylase
What helps create the transcription bubble in prokaryotes and Eukaryotes
Sigma factor in prokaryotes
tfiid in eukaryotes
What are the stages of transcription
Initiation Elongation and Transcription
what is the physiological inducer for lac operon gene
allolactose
What is the other inducer for the lac operon gene
Gratuitous Inducer - IPTG
What are the two positive regulations of the lac operon
Presence of lactose- leads to inactiovativation of the repressor
Absence of glucose- results in the activation of an activator called CRP
What is the function of CRP/CAP in the regulation of the lac operon
It makes more processive in transcribing the lac operon
Which RNA Pol. in Eukaryotes
What activates CRP
cAMP
What happens before initiation and after initiation that leads to elongation
Abortive transcription and then release of sigma factor which leads to elongation
How does CRP/ lac repressor ineract with RNA polymerase
Through protein protein interactions
How does the lac repressor and CRP identify their binding sites
Through helix-turn-helix motifs
What are the two ways of terminating transcription in prokaryotes
Rho-dependent termination a
Rho independent termination
How do the two ways of transcription termination in bacteria work
Rho dependent depend on Rho which has helicase activity and removes the RNA strand
Rho independents depend on signal/ termination sequence Which is a GC inverted repeat followed by an AT-rich region, G forms base pair with C forms the hairpin structure forcing the polymerase to release the RNA
What makes RNAP processive
The release of the sigma factor
Which transcription factor has the ability to identify the TATA box
TFIID
WHich transcription factors are the first and last to bind
First to bind-TFIID
Last to bind -TFIIH