Chiral proofreading during protein biosynthesis and its evolutionary implications. Issue 13 (29th June 2022)

• Record Type: Journal Article
• Authors: Kumar, Pradeep; Bhatnagar, Akshay; Sankaranarayanan, Rajan
• Is Part Of: FEBS letters. Volume 596:Issue 13(2022)
• Page Start: 1615
• Page End: 1627
• Publication Date: 2022-06-29
• Subjects: aminoacyl‐tRNA synthetase -- chiral proofreading -- d‐amino acids -- endosymbiosis -- Homochirality -- mitochondria -- protein biosynthesis -- translation of genetic code -- translation quality control -- tRNA; Biochemistry -- Periodicals; Biophysics -- Periodicals; Molecular biology -- Periodicals; Biochimie -- Périodiques; Biochemistry; Biophysics; Molecular biology; Periodicals; 572.05
• DOI: 10.1002/1873-3468.14419
• Languages: English
• ISSNs: 0014-5793

Abstract

Abstract : Homochirality of biomacromolecules is a prerequisite for their proper functioning and hence essential for all life forms. This underscores the role of cellular chiral checkpoints in enforcing homochirality during protein biosynthesis. d ‐Aminoacyl‐tRNA deacylase (DTD) is an enzyme that performs 'chirality‐based proofreading' to remove d ‐amino acids mistakenly attached to tRNAs, thus recycling them for further rounds of translation. Paradoxically, owing to its l ‐chiral rejection mode of action, DTD can remove glycine as well, which is an achiral amino acid. However, this activity is modulated by discriminator base (N73) in tRNA, a unique element that protects the cognate Gly‐tRNA Gly . Here, we review our recent work showing various aspects of DTD and tRNA Gly coevolution and its key role in maintaining proper translation surveillance in both bacteria and eukaryotes. Moreover, we also discuss two major optimization events on DTD and tRNA that resolved compatibility issues among the archaeal and the bacterial translation apparatuses. Importantly, such optimizations are necessary for the emergence of mitochondria and successful eukaryogenesis. Abstract : Here, we summarize various aspects of DTD and tRNA Gly co‐evolution and their key role in maintaining proper translation surveillance in both bacteria and eukaryotes. We also discuss two major optimization events on DTD and tRNA resulting from incompatibility issues among the archaeal and bacterial translation apparatuses for the emergence of mitochondria and successful eukaryogenesis.