4rrr

Publication Abstract from PubMed

Proofreading modules of aminoacyl-tRNA synthetases are responsible for enforcing a high fidelity during translation of the genetic code. They use strategically positioned side chains for specifically targeting incorrect aminoacyl-tRNAs. Here, we show that a unique proofreading module possessing a D-aminoacyl-tRNA deacylase fold does not use side chains for imparting specificity or for catalysis, the two hallmark activities of enzymes. We show, using three distinct archaea, that a side-chain-stripped recognition site is fully capable of solving a subtle discrimination problem. While biochemical probing establishes that RNA plays the catalytic role, mechanistic insights from multiple high-resolution snapshots reveal that differential remodelling of the catalytic core at the RNA-peptide interface provides the determinants for correct proofreading activity. The functional crosstalk between RNA and protein elucidated here suggests how primordial enzyme functions could have emerged on RNA-peptide scaffolds before recruitment of specific side chains.

Specificity and catalysis hardwired at the RNA-protein interface in a translational proofreading enzyme.,Ahmad S, Muthukumar S, Kuncha SK, Routh SB, Yerabham AS, Hussain T, Kamarthapu V, Kruparani SP, Sankaranarayanan R Nat Commun. 2015 Jun 26;6:7552. doi: 10.1038/ncomms8552. PMID:26113036^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.