18

Question 1

what binds to the mrna cap

Answer 1

eIF4E

Question 2

what binds to both cap binding protein eIF4E and the PABP

Answer 2

eIF4G

Question 3

what binds to the tail

Answer 3

PABP

Question 4

what is needed later to remove structure from mRNA when it is being scanned to locate the start codon

Answer 4

eIF4A and eIF4B

Question 5

what does eIF4F make up

Answer 5

eIF4A + eIF4E + eIF4G

Question 6

what describes the combination of euk initiation factors that associate with 5 and 3’ ends of mrna

Answer 6

eIF4F

Question 7

what is positioned before anticodon can pair to the start codon

Answer 7

initiator tRNA

Question 8

what blocks the E and A site

Answer 8

eIF1 + eIF1A

Question 9

what is the counterpart to IF2

Answer 9

eIF5B

Question 10

what guides the initiator tRNA into place in the P site

Answer 10

eIF2

Question 11

what may interact with eIF2

Answer 11

eIF1A

Question 12

what are the latent GTPases

Answer 12

eIF2

Question 13

when can eIF2 be activated

Answer 13

not unitl mRNA has been bound and start codon is positioned

Question 14

what helps mRNA bound and start codon is positioned

Answer 14

eIF3 and eIF5

Question 15

what interacts with eIF4G

Answer 15

eIF3

Question 16

what is the GAP protein for eIF2

Answer 16

eIF5

Question 17

when is eIF5 GAP activity active

Answer 17

when the start codon is found and matched

Question 18

what makes up the 48S or preinitiation complex

Answer 18

the small subunit, the initiator tRNA, 5 initiation factors

Question 19

what binds to the initiatior tRNA and delivers it to the P site

Answer 19

eIF2-GTP

Question 20

what does not bind to the initiator tRNA and instead releases it

Answer 20

eIF2-GDP

Question 21

what is a latent GAP protein

Answer 21

eIF5

Question 22

What brings the two complexes togethre

Answer 22

eIF3 and eIF4G

Question 23

what positions the start codon in the P site

Answer 23

scanning facilitated by eIF4A and eIF4B

Question 24

what can inhbiit the scanning process

Answer 24

secondary structures

Question 25

what moves the mRNA through the complex to let the initator tRNA cehck the codons for an AUG and also unqinds secondary structure

Answer 25

eIF4A and eIF4B

Question 26

what is a RNA helixase and ATPase

Answer 26

eIF4A

Question 27

when does initiation occur

Answer 27

at the first AUG but sometimes at the second or third

Question 28

what is the kozak sequence and what does it do

Answer 28

helps us know if we found the right AUG it is A/GXXAUGG

Question 29

what is the purpose of Rps26

Answer 29

plays a key role in recognizing As at positons 2 and 4 in the kozak sequence leading to preferential translation of mRNAs that contain these adenosines

Question 30

what does Rps26 depletion lead to

Answer 30

decreases the translation of normally high translated mRNAs

Question 31

what do Rps26 deficient ribosomes decode

Answer 31

a separate translational program not endoced by the kozak sequence

Question 32

what replaces eIF1 on the 40S ribosomal subunit to help promote start codon recognition

Answer 32

eIF5

Question 33

what happens after eIF5 replaces eIF1 on the 40S ribosomal subunit to help promote start codon recognition

Answer 33

inactive factor activities of eIF5 and eIF2 are activated

Question 34

when is the GAP activity of eIF5 activated

Answer 34

when the codon anticodon match is found for the initiator tRNA

Question 35

what happens when the GTPase activity of eIF2 is activated

Answer 35

the GTP bound to eIF2 is hydrolyzed to GDP thereby releasing most of the inhibition factors except for eIF5B(GTP)

Question 36

what is the purpose of GEF or GNEF

Answer 36

displace GDP and replace it with GTP in the some GTPases that bind to GDP more tightly than GTP

Question 37

which is a GNEF

Answer 37

eIF2B

Question 38

what is eIF2B a GNEF for

Answer 38

eIF2