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Residue-specific Incorporation of Noncanonical Amino Acids into Model Proteins Using an Escherichia coli Cell-free Transcription-translation System
Published on: August 1, 2016
Anticodon G recognition by tRNA synthetases mimics the tRNA core
Liron Klipcan1, Mark Safro, Paul Schimmel
1Department of Molecular Biology and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 N. Torrey Pines Road, La Jolla, CA 92037, USA.
Trends in Biochemical Sciences
|December 26, 2012
Summary
Early proteins may have mimicked RNA's guanine recognition. Amino acids in tRNA synthetases replicate ancient RNA interactions, suggesting a role in the genetic code's evolution.
Area of Science:
- Biochemistry
- Molecular Biology
- Origin of Life Research
Background:
- The RNA world hypothesis posits RNA preceded DNA and proteins.
- Nucleotide base recognition is fundamental to genetic information transfer.
- Transfer RNA (tRNA) synthetases are crucial enzymes linking amino acids to their cognate tRNAs.
Purpose of the Study:
- To investigate ancient RNA-based mechanisms for guanine recognition.
- To explore how early proteins, specifically tRNA synthetases, may have mimicked these RNA mechanisms.
- To propose a link between RNA recognition strategies and the evolution of the genetic code.
Main Methods:
- Comparative analysis of tRNA core structures and guanine recognition patterns.
- Structural and functional examination of anticodon binding domains (ABDs) in tRNA synthetases.
- Investigating amino acid side chain mimicry of RNA base interactions.
Main Results:
- A conserved tRNA structural motif for guanine recognition was identified.
- Nine diverse and nonhomologous tRNA synthetase ABDs were found to adapt this tRNA format.
- Amino acid side chains within these ABDs effectively mimic all interactions of the tRNA G22 base.
Conclusions:
- Early proteins likely adopted RNA-based recognition strategies for specific bases like guanine.
- The mimicry of RNA's guanine recognition by tRNA synthetases provides a potential evolutionary link.
- This RNA-mimicking mechanism may have influenced the selection of amino acids for the genetic code.
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