How N-formylmethionine (fMet) is only associated with the 5' AUG initiation codon and not with internal AUG codons, given that m

Question

aliya0001 [1]

2 years ago

7

How N-formylmethionine (fMet) is only associated with the 5' AUG initiation codon and not with internal AUG codons, given that m

ethionine in both cases in encoded by an AUG in the mRNA.

Biology

1 answer:

KonstantinChe [14] · Answer 1 · 2022-08-09T11:18:41+03:00

Answer:

Different transfer RNAs (tRNAs) selectively bind to N-terminal and internal AUG codons of bacterial polypeptides .

Explanation:

In prokaryotic organisms, N-formylmethionine (fMet) is coded by the start codon (AUG), thereby generating the most N-terminal residue of bacterial proteins. This residue (fMet) is a modified methionine amino acid that contains attached a formyl group to its amino group. Remarkably, it has been shown that formylmethionyl-tRNA only can bind to this initial AUG codon, while methionyl-tRNA binds to internal AUG codons.