During transfer RNA processing, nucleotides added post-transcriptionally at the 3' terminus form the sequence required for amino acid attachment. This terminal sequence is:

• A 5'-GCA-3'
• B 5'-AAC-3'
• C 5'-ACC-3'
• D 5'-CCA-3' ✓

Explanation

All mature tRNAs end in an invariant 5'-CCA-3' at the 3' acceptor arm, and the 3' terminal adenosine carries the esterified amino acid via its 2' or 3' hydroxyl group. In eukaryotes this trinucleotide is added post-transcriptionally by tRNA nucleotidyltransferase, whereas many bacterial tRNA genes encode it directly. ACC, AAC and GCA do not form the acceptor terminus and would not support aminoacylation by the synthetases.

Reference: Lehninger Principles of Biochemistry, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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