RT Journal Article
SR Electronic
T1 A chiral selectivity relaxed paralog of DTD for proofreading tRNA mischarging in Animalia
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 123919
DO 10.1101/123919
A1 Santosh Kumar Kuncha
A1 Mohd Mazeed,
A1 Raghvendra Singh,
A1 Bhavita Kattula,
A1 Satya Brata Routh,
A1 Rajan Sankaranarayanan
YR 2017
UL http://biorxiv.org/content/early/2017/06/08/123919.abstract
AB D-aminoacyl-tRNA deacylase (DTD), a trans-editing factor found in bacteria and eukaryotes, removes D-amino acids mischarged on tRNAs as well as achiral glycine mischarged on tRNAAla. An invariant cross-subunit Gly-cisPro motif forms the mechanistic basis of strict L-amino acid rejection from the catalytic site. Here, we present the identification of a DTD variant, named ATD (Animalia-specific tRNA deacylase), that harbors a Gly-transPro motif. The cis-to-trans switch causes a “gain of function” through L-chiral selectivity in ATD resulting in the clearing of L-alanine mischarged on tRNAThr(G4•U69) by eukaryotic AlaRS. The biochemical proofreading activity of ATD is conserved across diverse classes of phylum Chordata. Animalia genomes enriched in tRNAThr(G4•U69) genes are in strict association with the presence of ATD, underlining the mandatory requirement of a dedicated factor to proofread tRNA misaminoacylation. The study highlights the emergence of ATD during genome expansion as a key event associated with the evolution of Animalia.