Translation in Eukaryotes Flashcards
What are the major differences between prokaryotic and eukaryotic translation?
Ribosomes - Eukaryotes larger
Initiator tRNA - starting amino acid is methionine not fMet.
Initiation - in eukaryotes translation exists separately from transcription.
No shine-Dalgarno sequence in mRNA so signal translation - first AUG enough to signal in eukaryotes.
Each codon encodes for one type of protein only so we can just look for the start codon AUG and go from there to translate EACH protein.
What forms the initiation complex in Eukaryotes?
The 40S ribosome, initiator tRNA and eukaryotic initiation factors.
Where does the initiation complex bind to and what do the initiation factors do after it is bound in Eukaryotes?
5’ cap - some initiation factors (helicase) help initiation factor move along transcript using ATP until finds AUG.
What happens after the initiation complex binds to AUG in Eukaryotes?
Brings methionine and binds - initiation factors released from complex so the large 60S subunit can associate with the small 40S. Get 80S subunit.
How does the structure of Eukaryotic mRNA differ to prokaryotic? How does this occur?
Eukaryotic is circular. Proteins factors bind to the 5’ cap and 3’ tail and associate with each other.
What does the circularization of eukaryotic mRNA do?
Likely prevents translation of mRNA without a poly-A tail.
What is the equivalent to EFG in eukaryotes?
EF2 - also allows for translocation by moving subunit along.
How does organization of translational machinery in complexes associated with the cytoskeleton assist in translation?
Facilitates efficiency of protein synthesis.
