Lec6+7Translation Flashcards
How does tetracycline inhibit protein synthesis?
Binds to bacterial 30s ribosomal subunit and prevent attachment of aminoacyl-T RNAs to the acceptor site of the ribosome
After either 30 or 50s ribosomal subunit
What is the mechanism of tetracycline resistance that is related to ribosome function?
Tet (M,O,Q,S)= resistance genes that make a cytoplasmic protein that interact with ribosome making it insensitive to tetracycline
What is the binding site for a lot of proteins?
the phosphate on the CTD of RNA pol 2
to hop on the RNA as its being synthesized
What is a glob?
Globs is what we see in real life, RNA is covered with proteins
What is the nuclear export/pore receptor?
finds nuclear uses ATP to get mRNA out
T/F the only thing needed for mRNA to leave is the nuclear export receptor
FALSE, YOU ALSO NEED ATP
What do SR do?
Recruites splicesomes
What do hNRNP do?
block the spliceosome proteins
RNA poly 2 has ____ ____ where ____ ____ are looking for place to add cap and they end up generating ____ that will interact with this complex for initiating factors for _____
Phos CTD; cap enzymes; RNAs; ribosomes
MRNA-cap binding complex:
5’cap interacts
Nucelar pore complex
aqueous channel to cytoplasm
diffusion for small molecules only (less than 50K daltons)
Nuclear export receptor needed for macromolecules, including finished mRNAs
For nucelar pore complex, diffusion is for small or late molecules? Tell me the important number size (NEED TO KNOW)
SMALL
<50K daltons
For nucelar pore complex, diffusion is for small or late molecules? Tell me the important number size (NEED TO KNOW)
SMALL
<50K daltons
Where does the catalytic energy come from since we do not have a protein that is peptide bond synthetase?
catalytic energy comes from rRNA
What happens in the nucleolus
Nucleolous is what we assemble RNA with
Polypeptides
-Creates large and small subunits of ribosomes
-Enzymes involved in processing of rRNA
Assembly w/ snoRNA
-Telomerase assembling with its RNA
Nucleolus assembles with the rRNA genes
The big rRNA gene is the starting point for creating the nucleolus
what assembles with the nucleolus
rRNA genes
What is the starting point for creating nucleolus?
big rRNA
What four rRNAs are needed for the completed Rb
18S,5.8S, 28S from one gene (nucleolus forms from this gene cluster)
5S from another gene (this is IMPORTED INTO THE NUCLEOLUS
What rRNA is imported into the nucleolus
5S
What are the large subunit rRNAs
5.8S, 28S, 5S
What is the small subunit rRNA
18s
Remember: mRNA can be translated once or many times?
many times to make many proteins
what do rRNA with modification function as?
catalysis the peptide bond, facilities the tRNA codon interaction
rRNA are gene duplicates or gene differences? explain
gene duplicates
exact duplicates we can only transcribe them once to only make one ribosome from rRNA transcime
there is no splicing (IVS instead)
What is the universal genetic code
Codons represent three nucleotides
REDUNDANCY is expected because there are only 64 combo of 3 nucleotides but only 20 AA
3 stop codes so 64-3 = how many combination that encode AA
If we have 64 combo, how many combinations will we have that encode AA
64-3=61
What is reading Frame shift
If we shift the reading frame, we shift the meaning of the codon, you can also tune into a stop codon very quickly
Cancers contain a lot of Fram shift mutation and end up with a truncated protein
**translate different proteins
Where does the amino acid attached to on the tRNA
3’ on the tRNA
what is the codon on 3’ of tRNA
CCA
For the CCA is it an independent of dependent template
independent
What is on the 5’ on the tRNA
Anticodon on tRNA for the codon on mRNA to bind
Where is the anticodon located
tRNA
where is the codon located
mRNA
What needs to be recognized for AA to bind
Modification spread around the tRNA,enzymes adding the AA to the tRNA need to recognize the tertiary structure of tRNA created by modifications
There are how many amino acetyl transferase enzymes?
20
What do acetyl transferase enzymes do?
That will only charge tRNA with a specific AA and recognize a different tertiary structure
Humans have __ different anticodons (____) but there are __ codons (mRNA) that code for amino acids
48 different anticodons (tRNA) but there are 61 codons (mRnA) that code for amino acids
Does we have mismatch in anticodon and codons, what do we do?
Wobble (IMPERFECT W/C BP) and it gives an extra bond to stabilize–> tRNA need flexibility
tRBA redundancy
Is wobble imperfect or perfect W/C BP
imperfect
What is added for wobble
Inosine purine before R group added for A or G
Where is the inosine added for woddle
ANTICODON 5’
tRNA base modifications help with “wobble” and provide what?
binding sites for aminoacyl-tRNA-synthetases that charge the tRNAs with amino acids
What are other modification besides inosine (lower yield)
4-thiouridine
N,N dimethyl G
Dihyrdo U
What do aminoacyl-tRNA synthetases need and what drives the reaction?
ATP is needed, pyrophosphates drives the reaction
What is aminoacyl-tRNA-synthetases doing?
added the amino acid to the tRNA on the 3OH via A.A.’s carbonyl groupie so that way the amino group is available to attach the carboxyl group of the preceding tRNA
Is tRNA synthetase specific of nonspecific for a particular amino acid? give example
specific!!!!
tRNA synthetase (tryptophanyl tRNA synthetase) with the amino acid tryptophan