RNA Metabolism Flashcards
What structure can RNA molecules fold into?
Bulge,Internal Loop, Hairpin
Order the types of RNA from most to least common?
rRNA, tRNA, mRNA other forms
Describe the Process of Transcriptional Initiation in E. Coli
Describe the Process of Initiation at RNA Pol I?
Describe the initiation process at RNA Pol III
Process of Initiation at RNA Pol II
Actinomycin: Action and Mechanism
Intercalates between G and C residues
inhibits transcriptional elongation in pro and eukaryotes
Rifampicin: Action and Mechanism
binds the beta subunit of bacterial RNA polymerase
blocks promter clearance
Aplha amanitin
comes from a death cap mushroom
inhibits RNA pol II greatly and is a weak inhibitor of RNA pol III
Draw the Nuclear Splicing Mechanism
Describe the processing of 3’ mRNA
rRNA processing in Eukaryotes
rRNA processing in Prokaryotes
tRNA processing
What occurs in the initiation, elongation, and termination sequences of RNA pol II?
Initiation occurs after phosporylation of the C-terminal domain of RNA Pol II by TFIIH
Elongation begins after the synthesis of the initial 60-70 ribonucleotides when TFIIE and TFIIH are kicked off and elongation factors bind
Termination starts with polyadenylation or 3’ end formation
What is the secondary action of TFIIH?
TFIIH is involved in transcription coupled DNA-repair subunits of TFIIH interact with the encountered lesion and recruit the whole nucleotide exision repair complex
What are the post transcriptional modifications done to rRNA, mRNA and tRNA respectively?
rRNA - methylation, nucleolytic cleavage
mRNA - 5’ cap, polyadenylation, removal of introns (nuclear splicing)
tRNA - 5’ and 3’ cleavage, CCA addition, base modification, tRNA splicing
