2. Protein Synthesis

6. tRNAs

7. • tRNAs are interpreters of the genetic code
• Length = 73 – 95 bases
• Have extensive 2o structure
• Acceptor arm – position where amino acid
attached
• Anticodon – complementary to mRNA
• Several covalently modified bases
• Gray bases are conserved between tRNAs

8. tRNAs: 2o vs 3o Structure

11. Aminoacyladenylate Formation
NH2
N
N
N
N
O
O
O
H
H OH
H
P
O
O
O-
P
O-
O
O
P
O-
ONH2
H
OH
O
N
N
O
C
CH
N
H
N
O
PPi
NH2
O
O
H
H OH
H
P
O-
O
H
OH
O
C
CH
NH2
H

12. Aminoacyl-tRNA Synthetase Rxn
NH2
NH2
N
N
N
N
5' tRNA
N
N
O
O
O
H
H OH
H
H
OH
P
O-
O
H
H
C
N
O
O
O
N
H
O
H
OH
H
CH H
NH2
NH3+
N
AMP
5' tRNA
N
O
O
H
H
O
H
O
H
OH
C
CH H
NH3+
N
N