Activation or Amino-acylation

Question 1

Purpose?

Answer 1

To attach the a correct amino acid to its tRNA @ 3’end

Question 2

ATP dependent or independent?

Answer 2

Dependent

Question 3

Enzyme?

Answer 3

Amino-acyl tRNA synthetases

Question 4

Recignizes (in the tRNA)

Answer 4

1. Acceptor arm
2. Anticodon loop

Question 5

Second genetic code?

Answer 5

Interaction between Amino-acyl tRNA synthetases and tRNA

Question 6

1st step of amino-acylation?

Answer 6

a.a + ATP—————adenylation—— aa-AMP

Question 7

2nd step?

Answer 7

a.a-AMP + tRNA ———— tRNA a.a-AMP

AMP get released.

tRNA a.a

Question 8

Amino-acyl tRNA synthetases Types/Class?

Answer 8

Class1
Class 2

Question 9

Class 1?

Answer 9

Add a.a @ 2’OH (Monomer mostly/Dimer)

Question 10

Class 2?

Answer 10

Add a.a @ 3’OH (Dimer/Tetramer)

Question 11

aaRS recognises?

Answer 11

Acceptor arm (mainly)

Anticodon Loop

Question 12

No. of Ntds. get involved in recognising tRNA by aaRS?

Answer 12

10 or more

Question 13

Important determinant for the specificity of tRNA Synthetase recognition

Answer 13

Acceptor arm

Question 14

which is known as Discriminator base?

Answer 14

Acceptor arm

Question 14

change in ______ base od acceptor arm , is sufficient to convert the recognition specificity from one aaRS to other.

Answer 14

Single base

Question 15

From bacteria to humans, The primary determinant of tRNA recognition by Ala-tRNA synthetases

Answer 15

is the presence of a single G=U base pair in the tRNA-Ala.

Question 16

Even a very short RNA strand (just 7 base pairs long), if structured in a minihelix (a small loop or hairpin shape), can be recognized and charged with alanine by the Ala-tRNA synthetase. if it has _____

Answer 16

G=U base pair

Question 17

Pathways for amino-acylation?

Answer 17

2 pathways

1. Direct pathway
2. Indirect Pathway