Poly (A) tail of m-RNA translates into which of the following polypeptides?
High-Yield Explanation
Ans. b. Polylysine (Ref: Harper 28/e p362, 27/e p366; Lippincott's 4/e p432, 424-27)Poly (A) tail of m-RNA translates into Polylysine.CodonAAAGGGCCCTTT/UUUTranslation productLysinQGlycineProlinePhenylalanine "Poly A tail is translated into the polylysine tail as AAA is the codon for lysine amino acid. Messenger RNAs, particularly in eukaryotes, have some unique chemical characteristics. The 5' terminal of mRNA is capped by a 7-methylguanosine triphosphate. The cap is involved in the recognition of mRNA by the translating machinery, and it probably helps stabilize the mRNA by preventing the attack of 5' -exonucleases. At their 3' end, most eukaryotic mRNAs have a suing of 80 to 250 adenylate residues, making up the poly (A) tail. The poly (A) tail and its associated proteins help protect mRNA from enzymatic destruction."