Finkelstein AV. The Reverse Side of a Coin: "Factor-Free" Ribosomal Protein Synthesis In Vitro is a Consequence of the In Vivo Proofreading Mechanism.
Biomolecules 2019;
9:E588. [PMID:
31597374 PMCID:
PMC6843673 DOI:
10.3390/biom9100588]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2019] [Revised: 09/28/2019] [Accepted: 10/03/2019] [Indexed: 11/17/2022] Open
Abstract
This paper elucidates a close connection between two well-known facts that until now have seemed independent: (i) the quality control ("proofreading") of the emerging amino acid sequence, occurring during the normal, elongation-factor-dependent ribosomal biosynthesis, which is performed by removing those Aa-tRNAs (aminoacyl tRNAs) whose anticodons are not complementary to the exhibited mRNA codons, and (ii) the in vitro discovered existence of the factor-free ribosomal synthesis of polypeptides. It is shown that a biological role of proofreading is played by a process that is exactly opposite to the step of factor-free binding of Aa-tRNA to the ribosome-exposed mRNA: a factor-free removal of that Aa-tRNA whose anticodon is not complementary to the ribosome-exhibited mRNA codon.
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