Wobble_Hypothesis and its antibiotic agents

WOBBLE HYPOTHESIS

1. WOBBLE HYPOTHESIS

2. CODON–ANTICODON PAIRING 5' 5' 3' 3'

3. WOBBLE HYPOTHESIS Wobble hypothesis was proposed by Francis Crick The first two bases in the codon create the coding specificity, for that they form strong Watson-Crick base pairs and bond strongly to the anticodon of the tRNA whereas third base of the codon some times binds rather loosely to the first base of anticodon i.e. third base of codon “wobbles”. So it is called wobble Hypothesis.

4. While reading  5'  to  3'  the first nucleotide in the anticodon (which is on the t RNA and pairs with the last nucleotide 3' of the codon on the mRNA), determines how many codons this t RNA actually distinguishes. If the first nucleotide in the anticodon is a C or an A , pairing is specific i.e. pairs with G or U of codon and acknowledges original Watson-Crick pairing i.e. only one specific codon can be paired to that t RNA .

5. 4. If the first nucleotide in the anticodon is U or G, the pairing is less specific and in fact two bases A,G or C,U can be interchangeably recognized by the tRNA i.e . Two specific codon can be paired to that tRNA . 5. Inosinate (I)  displays the true qualities of wobble, in that if the first nucleotide in the anticodon is I , then any of three bases A, C, U, in the original codon can be matched with the t RNA i.e. Three specific codon can be paired to that tRNA .

6. 6 . The minimum requirement to satisfy all possible codons (61 excluding three stop codons) is 32 tRNAS . That is 31 tRNA's for the amino acids and one initiation codon.

7. t RNA 5' anticodon base m RNA 3' codon base A U C G G C  or  U U A  or  G I A  or  C  or  U t RNA base pairing schemes The original wobble pairing rules, as proposed by Crick. Watson-Crick base pairs are shown in  bold , wobble base pairs in Italic .

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