Question:
Identify the order of post-trancriptional processing of yeast tRNA$^{\text{Tyr}$
(A) Addition of -CCA sequence at 3' end of tRNA
(B) Modification of Uridine to Dihydrouridine
(C) Removal of leader sequence from 5' end of tRNA
(D) Self splicing for removal intervening sequence
Choose the correct answer from the options given below:
Identify the order of post-trancriptional processing of yeast tRNA$^{\text{Tyr}$
(A) Addition of -CCA sequence at 3' end of tRNA
(B) Modification of Uridine to Dihydrouridine
(C) Removal of leader sequence from 5' end of tRNA
(D) Self splicing for removal intervening sequence
Choose the correct answer from the options given below:
(A) Addition of -CCA sequence at 3' end of tRNA
(B) Modification of Uridine to Dihydrouridine
(C) Removal of leader sequence from 5' end of tRNA
(D) Self splicing for removal intervening sequence
Choose the correct answer from the options given below:
Show Hint
tRNA processing always begins at the 5' end with RNase P cutting off the leader sequence.
Splicing and base modifications follow to yield the folded, mature cloverleaf structure.
Splicing and base modifications follow to yield the folded, mature cloverleaf structure.
Updated On: Jul 21, 2026
- (C), (D), (A), (B).
- (A), (C), (B), (D).
- (B), (A), (D), (C).
- (C), (B), (D), (A).
Show Solution
Verified By Collegedunia
The Correct Option is A
Solution and Explanation
Step 1: Understanding the Concept:
Transfer RNAs (tRNAs) are synthesized as larger precursor molecules (pre-tRNAs) that must undergo several successive enzymatic post-transcriptional processing steps in the nucleus before they are exported to the cytoplasm as functional, mature tRNAs.
Detailed Explanation:
Let us analyze the order of events in the maturation of eukaryotic pre-tRNA$^{\text{Tyr}}$:
1. Removal of the 5' leader sequence (C): The first processing step is the cleavage of the 5' leader sequence by the endonuclease ribozyme, RNase P.
2. Intron Splicing (D): Eukaryotic pre-tRNA$^{\text{Tyr}}$ contains an intervening intron sequence located in the anticodon loop. This intron is removed by a tRNA-specific endonuclease and ligated by a tRNA ligase.
3. Addition of the -CCA sequence at the 3' end (A): The 3' trailer sequence is removed by RNase D, and the invariant 3' -CCA sequence (the site of amino acid attachment) is added by the enzyme nucleotidyltransferase.
4. Base Modification (B): Specific bases are enzymatically modified to form non-standard nucleotides, such as the reduction of uridine to dihydrouridine (D) in the D-loop, which stabilizes the tertiary structure of the mature tRNA.
Therefore, the correct chronological order is (C) $\rightarrow$ (D) $\rightarrow$ (A) $\rightarrow$ (B).
Step 2: Final Answer:
The correct processing sequence corresponds to option (A).
Transfer RNAs (tRNAs) are synthesized as larger precursor molecules (pre-tRNAs) that must undergo several successive enzymatic post-transcriptional processing steps in the nucleus before they are exported to the cytoplasm as functional, mature tRNAs.
Detailed Explanation:
Let us analyze the order of events in the maturation of eukaryotic pre-tRNA$^{\text{Tyr}}$:
1. Removal of the 5' leader sequence (C): The first processing step is the cleavage of the 5' leader sequence by the endonuclease ribozyme, RNase P.
2. Intron Splicing (D): Eukaryotic pre-tRNA$^{\text{Tyr}}$ contains an intervening intron sequence located in the anticodon loop. This intron is removed by a tRNA-specific endonuclease and ligated by a tRNA ligase.
3. Addition of the -CCA sequence at the 3' end (A): The 3' trailer sequence is removed by RNase D, and the invariant 3' -CCA sequence (the site of amino acid attachment) is added by the enzyme nucleotidyltransferase.
4. Base Modification (B): Specific bases are enzymatically modified to form non-standard nucleotides, such as the reduction of uridine to dihydrouridine (D) in the D-loop, which stabilizes the tertiary structure of the mature tRNA.
Therefore, the correct chronological order is (C) $\rightarrow$ (D) $\rightarrow$ (A) $\rightarrow$ (B).
Step 2: Final Answer:
The correct processing sequence corresponds to option (A).
Was this answer helpful?
0
0
Top ICAR AIEEA Animal Biotechnology Questions
- Acid phosphatase is the marker enzyme for
- The primary amino acids generally present in mammalian proteins are
- Sodium/Potassium ATPase is the marker enzyme for
- Polysaccharide present in bacterial cell wall is
- Fluid mosaic model of cell membrane is given by
View More Questions
Top ICAR AIEEA Molecular Biology Questions
- Approximate numbers of proteins present in 40 S subunit of mammalian ribosomes are
- 40 S subunit of mammalian ribosomes contain
- Acetylation of histones H3 and H4 is associated with
- Given below are two statements, one is labelled as Assertion (A) and other one labelled as Reason (R).
A : The ends of the chromosomes contain structures called telomeres
R: DNA dependent DNA polymerase is the enzyme responsible for telomere synthesis
In light of the above statements, choose the most appropriate answer from the options given below . - Common covalent modifications in core histone proteins include:
(A) Acetylation
(B) Methylation
(C) Phosphorylation
(D) ADP-ribosylation
Choose the correct answer from the options given below:
View More Questions
Top ICAR AIEEA Questions
- Which of the following statements is false?
- Which of the following is an example of an inventory?
- According to Adam Smith, productivity gains could be brought about through .
- The supply curve for an artificially scarce good is .
- Which of the following would not be considered an opportunity cost of paid employment?
View More Questions