Suppose a mutation occurs in the gene for a particular aminoacyl-tRNA synthetase. The mutation changes which amino acid is recognized, without affecting which tRNA molecule is recognized. How is this likely to affect protein synthesis?Find all that apply.
It will change the location of start sites during transcription.
It will change the sequence of bases in processed mRNAs.
It will change the location of splice sites in pre-mRNAs.
It will change the sequence of amino acids in polypeptide chains.
It will cause premature termination of translation.
It will affect the synthesis of only a few types of protein produced by the cell.
It will affect the synthesis of most of the proteins produced by the cell.
The given scenario describes a mutation in the gene for a specific aminoacyl-tRNA synthetase, which changes the amino acid recognized without affecting the tRNA molecule recognized. This mutation is likely to affect protein synthesis in the following ways:
1. It will change the sequence of amino acids in polypeptide chains:
Aminoacyl-tRNA synthetases are responsible for attaching the corresponding amino acids to their corresponding tRNA molecules in protein synthesis. By changing which amino acid is recognized, the mutant synthetase will incorporate a different amino acid into the growing polypeptide chain, altering its sequence.
2. It may cause premature termination of translation:
Since the mutant synthetase will recognize a different amino acid, it may introduce a premature stop codon into the mRNA sequence. This premature termination can result in truncated or non-functional proteins.
3. It will affect the synthesis of only a few types of protein produced by the cell:
Aminoacyl-tRNA synthetases are responsible for specific amino acid-tRNA pairings. As the mutation only changes which amino acid is recognized without affecting the tRNA molecule recognized, it will impact the synthesis of proteins that require the changed amino acid. This means that only a subset of proteins that use that particular amino acid will be affected, not all proteins produced by the cell. Other aminoacyl-tRNA synthetases will continue to function normally.
Therefore, the correct answers are:
- It will change the sequence of amino acids in polypeptide chains.
- It may cause premature termination of translation.
- It will affect the synthesis of only a few types of protein produced by the cell.