1. Generic Structure of a Eukaryotic mRNA
5’-untranslated region (5’-UTR)
3’-untranslated region (3’-UTR)
AUG
UAA
Open Reading Frame
(ORF)
(AUUUA)n
7-Me-GpppG
(AAA)n
stem-loop
structures
stem-loop
structures
cleavage
& poly(A)
addition
site
cap
poly(A) tail
Initiation codon context
G C C A C C G
Kozak (mammalian) consensus:
(GC-poor) A x A (U)
S. cerevisiae (yeast) consensus:

2. 7-methyl-guanine
R1 and R2 = H or CH3
mRNA-3’-OH

3. • ATP and GTP
• GTP

4. Gcn2 &
other eIF2
kinases

5. Mammalian eIF4G1

7. eIF4E

8. eIF3 eIF4G mRNA 40S subunit Composed of 13 distinct gene products
(eIF3a-eIF3m)
mRNA
40S subunit

10. eIF3

11. Translation Factor
Yeast Gene Name
Size (residues)
Function / Comments
eIF4E
CDC33
213
7MeG cap-binding protein
eIF4E-BP1
CAF20
161
Cdc33-binding protein
eIF4E-BP2
EAP1
632
eIF4G1
TIF4631
952
Scaffold protein, isoform 1
eIF4G2
TIF4632
914
Scaffold protein, isoform 2
eIF4A1
TIF1
395
RNA-dependent RNA helicase, isoform 1
eIF4A2
TIF2
RNA-dependent RNA helicase, isoform 2
eIF4B
TIF3
436
RNA-binding protein, stimulates eIF4A
PAB
PAB1
577
Poly(A)-binding protein
eIF3a
TIF32 / RPG1
964
p110 subunit of eIF3
eIF3b
PRT1
763
p90 subunit of eIF3, RNA-binding protein
eIF3c
NIP1
812
p93 subunit of eIF3, required for nucleocytoplasmic transport of eIF3
eIF3g
TIF35
274
p33 subunit of eIF3, RNA-binding protein
eIF3i
TIF34
347
p39 subunit of eIF3, two WD40 repeats
eIF3j
HCR1
265
p29 subunit of eIF3, binds to A site and mRNA entry channel of 40S
eIF3 ?
SUI1
108
p16 subunit of eIF3, involved in initiation codon recognition
TIF31 / CLU1
p135 subunit of eIF3, role in scanning for AUG
GCD10
478
p62 subunit of eIF3, RNA-binding protein
GCD14
383
tRNA 1-methyladenosine methyltransferase, when associated with Gcd10