Chiral proofreading during protein biosynthesis and its evolutionary implications

FEBS Letters

article

Pradeep Kumar¹  Akshay Bhatnagar¹  Rajan Sankaranarayanan¹ 

[1] CSIR–Centre for Cellular and Molecular Biology;Academy of Scientific and Innovative Research ,(AcSIR), CSIR–CCMB campus

关键词: aminoacyl-tRNA synthetase;    chiral proofreading;    d-amino acids;    endosymbiosis;    Homochirality;    mitochondria;    protein biosynthesis;    translation of genetic code;    translation quality control;    tRNA;   

DOI  :  10.1002/1873-3468.14419

来源: John Wiley & Sons Ltd.

【 摘 要 】

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.

【 授权许可】

Unknown