Initiation of eukaryotic translation Flashcards
Is translation initiation much simpler in bacteria or in eukaryotic cytosol?
In bacteria
Do cap-binding and tail-binding proteins recognise each other?
Yes, so eukaryotic mRNA is a ‘non-closed’ loop during translation
What are the initiation codons?
AUG»_space; GUG
What is the special initiator tRNA?
tRNAi
Does eukaryotic translation involve transformylase?
No
How is eukaryotic translational initiation different from prokaryotic translational initiation?
- No Shine-Dalgarno (S-D) recognition (RNA-RNA)
- 40S binds to mRNA-CAP (protein-protein)
- Complexity_multiplicity of eIFs
What are the functions of eIFs?
- Bind to ribosomal subunits: eIF1, eIF1A, eIF3, eIF5, eIF6
- Bind to met-tRNAi: eIF2
- Bind to mRNA CAP: eIF4 group
- Release other eIFs: eIF5, eIF5B
What are the functions of eIFs?
- Bind to ribosomal subunits: eIF1, eIF1A, eIF3, eIF5, eIF6
- Bind to met-tRNAi: eIF2
- Bind to mRNA CAP: eIF4 group
- Release other eIFs: eIF5, eIF5B
How many factors does eIF1 contain?
2 (1+1A)
How many subunits does eIF2 contain?
3
How many subunits does eIF2B contain?
5
How many subunits does eIF3 contain?
13-8
How many factors does eIF4 contain?
4 (4A, 4B, 4E, 4G)
How many factors does eIF5 contain?
2 (5+5B)
How many polypeptide does eIF6 contain?
A single polypeptide
