MBM Flashcards
Rho-independent vs rho-dependent RNA termination mechanism in Prokaryotes
Ind: hairpin loop and polyA sequence with a string of uracil
Dep: Rho Helicase binds to rut site with ATP
Pol α:
Tight complex with Primase
Function of PERK in Eu Translation?
Phosphorylates eIF2-GDP to eIF2-GTP, in order to inhibit eIF2B. (2B promotes translation)
3 mRNA Mods
5’ cap, splicing, 3’ poly-A-tail
Tetracyclin
Blocks pro A site
How to remember which letters are found in the basal transcription machinery?
Letters A-H, except there’s NO C
The C-Terminal end of Polymerase must be (phos or dephos) to recruit termination factors?
Dephosphorylated
Base Excision Repair 3 Steps (Mainly to fix mutations caused by environmental factors)
- DNA Glycosylase cleaves sugar link
- AP endonuclease cuts phosphodiester
- Pol 1 And Ligase f
Streptomycin
Alters 30S only Pro
What two things can bind when TF-IIH phosphorylates the C-terminus of RNA POL II?
Cap Synthesizing complex (CSC) and cap binding complex (CBC) can link onto it and hook onto the growing mRNA
Three steps in Eukaryotic Translation Initiation
- eIF4F bind cap and 40S
- eIF2 links Met
- Complex slides down with helicase towards AUG site
Three steps in Eukaryotic DNA initiation?
- ORC is activated by Cdt1 and Cdc16/18
- MCM helicase is recruited
- After replication is done; Cdt1 is inhibited by geminin and Cdc6/18 is degraded.
Four steps for protein Elongation
- aaTRNA binds A site with EF-TU-GTP
- GTP regenerated with TS
- Large subunit catalyzes peptide bond formation
- EF-G or eEF2 binds to A site and slides to next unit
Three steps in Prokaryotic DNA initiation?
- dnaA protein binds to region in origin
- dnaB helicase unwinds
- Primase is recruited
Erythromycin
Blocks Pro A site
Pro vs Eu Small rRNA identity and function
Pro-16S,
Eu-18S, They both line up the mRNA
Two methods of Self Splicing mRNA?
- Guano-Nucleotide facilitates attack
2. Adenosine Branch point links OH, forms loop
Is pro or Eu mRNA monocistronic?
Eu, one gene per transcript
The mRNA sequence is complementary to the____ strand and identical to the ___ strand
Template, Coding
Three Eukaryotic RNA polymerases
Pol 1 and Pol3-rRNA and tRNA
Pol2-mRNA
Distinguishing factor of Prokaryotic DNA pol III?
Holocomplex consisting of both lagging strand and leading strand polymerases connected.
Cycloheximide
Blocks peptidyl transferase site in eukaryotes!
a-amanitin
Blocks Eukaryotic PolII
3 Components of mRNA 5’ cap before it’s attached
- 7-methyl-guanosine cap
- 5’5’-Triphosphate linkage
- Sometimes methylation at 2’ OH group of bases
Pol δ and Pol ε
Promotes both lagging and leading strand synthesis
Mismatch Repair (Mistakes made by DNA polymerase) 4 Steps
- MutS and MutL search for defects and make a complex
- MutH is recruited and makes a nick
- DNA helicase and Exonuclease
- DNA Pol 3 Fills gap!
Describe the Six subunits of RNA polymerase of prokaryotes.
2 alphas
1 Beta 1 Beta’-SYNTHESIS
1 Omega
1 Sigma-RECOGNITION AND BINDING OF PROMOTER
Distinguishing factor of Prokaryotic DNA Pol I?
5’->3’ exonuclease activity
Rifampicin
Inhibits prokaryotic RNA transcription
Basal Transcription Machinery, Chromatin Modifications, Transcription activators, Coactivators, and architectural regulators are the 5 main things which ____ needs to bind
EUKARYOTIC POLYMERASE 2
Nucleotide Excision Repair 3 Steps (Mainly for pyrimidine dimers)
- UvrABC detects large distortions
- UvrD(helicase) unwinds DNA and peels
- Pol 1 and Ligase
Glycl-tRNA synthetase (GARS) mutations causes
Chargot Marie Tooth
Puromycin
Premature Pro Termination
To get the 7’ methyl guanosine cap on mRNA, what two key things need to happen via TF-IIH
- Phosphoydrolase chopping gamma phosphate
2. Guanine getting linked on by guanylyltransferase
Pol γ
Mitochondrial DNA Rep
Actinomycin D
Inhibits BOTH eukaryotic and prokaryotic RNA transcription
Three steps in prokaryotic Translation Initiation?
- IF1 blocks A site, IF3 keeps Large subunit away
- 30S binds to mRNA with 16S/ShineDalgarno
- fMet added via IF2
Basal Machinery Functions
IID, IIA:
IIB, IIF:
IIE and IIH
- Binds to TATA, stabilizes
- recruits F, which carries Pol
- Helicase activity
Pro vs Eu Large rRNA identity and function
Pro- 23S, Eu-28S
They both catalyze peptide bond formation
Name the regulatory component of mRNA’s function and one structure
Controls timing and quantity of mRNA; includes promoter
Pol β
Base Excision Repair
The 4 structural component of mRNA
- Exons
- Introns
- splice junctions,
- polyadenylation Signal
How many RNA polymerases do prokaryotes have?
One