Explain “Wobble Hypothesis” with the help of a suitable diagram.
Hint: The Wobble hypothesis explains the redundancy of codons. Codons are sets of three nucleotides that specify an amino acid. These codes are composed of adenine, guanine, cytosine, and thymine in DNA, and uracil in RNA. For instance, the codon AUG corresponds to methionine.
Complete answer:
The pairing of nucleotide bases follows the rule where adenine pairs with thymine and cytosine pairs with guanine. This is referred to as Watson and Crick pairing.
The Wobble hypothesis suggests that genetic codes are redundant. It proposes that the third base pairing can vary, such as guanine pairing with thymine or uracil.
The third base in a codon is referred to as the Wobble site. The third base in a codon is referred to as the Wobble site.The key feature of this position is that when the codon binds to mRNA, the tRNA is more flexible at the third codon position. This flexibility allows for non-standard base pairing at this site.
Codon redundancy arises from the structure of the tRNA anticodon. The wobble pairing between the tRNA anticodon and mRNA occurs starting from the 5′ end of the codon. The third base pair is less crucial once the other positions are matched, enabling the translation of mRNA with fewer tRNAs.
Note: This hypothesis was clearly demonstrated in *E. coli*. Wobble base pairs are more thermally stable compared to the Watson-Crick pairs. Wobble pairing is commonly observed in the secondary structure of RNA and plays a crucial role in the translation of the genetic code.