Question

IleRS uses a double-sieve mechanism to accurately produce ${\mathbf{lletRNA}}^{\mathbf{lle}}$ and prevent the synthesis of$\mathbf{Val}\mathbf{-}{\mathbf{tRNA}}^{\mathbf{lle}}$ . Which other pairs of amino acids differ in structure by a single carbon and might have aaRSs that use a similar double-sieve proofreading mechanism?

Short answer

Gly and Ala, Val and Leu, Ser and Thr, Asn and Gln, and Asp and Glu are the amino acid pairs with single carbon differences that can be used in the double-sieve proofreading mechanism.

Step-by-step solution

Definition of Concept

The t RNA Val 1 undergoes alkylation at the third nucleotide from the 5'-terminus of the modifying agent's binding site. Valyl-tRNA synthetase from baker's yeast catalytic mechanism.

Pairs of amino acids differ in structure by a single carbon

The other pairs of amino acids that differ in structure by a single carbon and can be used in the double-sieve proofreading mechanism are:

• Gly and Ala ( H and${\text{CH}}_3$)
• Val and Leu (difference in additional ${\text{CH}}_2$of Leu)
• Ser and Thr (difference in polar side chains)
• Asn and Gln (difference in additional ${\text{CH}}_2$of Gln)
• Asp and Glu difference in additional ${\text{CH}}_2$ of Glu)