tRNA reads the genetic code through complementary base-pairing with mRNA. According to Chapeville et al. (1962) and Grunberger et al. (1969), tRNA molecules act as adaptors, using one end to recognize the triplet code in mRNA and the other to carry a specific amino acid.
The Role of tRNA in Decoding mRNA
tRNA molecules are crucial in translating the genetic code from mRNA into a protein sequence. Here's a breakdown of how tRNA accomplishes this:
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Adaptor Function: tRNA serves as an "adaptor" molecule, bridging the gap between the nucleotide sequence in mRNA and the amino acid sequence in a polypeptide.
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Anticodon Region: One end of the tRNA molecule contains a three-nucleotide sequence called the anticodon. This anticodon is complementary to a specific three-nucleotide codon on the mRNA molecule.
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Base Pairing: The anticodon of the tRNA binds to the mRNA codon through complementary base-pairing. For example, if the mRNA codon is 5'-AUG-3', the tRNA anticodon would be 3'-UAC-5'. This ensures that the correct amino acid is added to the growing polypeptide chain.
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Amino Acid Attachment: The other end of the tRNA molecule is attached to a specific amino acid. This attachment is facilitated by enzymes called aminoacyl-tRNA synthetases, which ensure that each tRNA is charged with the correct amino acid.
Illustrative Table of Codon-Anticodon Pairing
| mRNA Codon | tRNA Anticodon | Amino Acid |
|---|---|---|
| AUG | UAC | Methionine |
| GGC | CCG | Glycine |
| UCA | AGU | Serine |
Summary
In essence, tRNA reads the genetic code by recognizing specific mRNA codons through complementary base-pairing via its anticodon region, ensuring that the correct amino acid is delivered for protein synthesis.
