David B. F. Johnson and Lei Wang1
-Author Affiliations
The Jack H. Skirball Center for Chemical Biology and Proteomics, The Salk Institute for Biological Studies, La Jolla, CA 92037
Edited* by Peter G. Schultz, The Scripps Research Institute, La Jolla, CA, and approved March 18, 2010 (received for review January 19, 2010)
Source/Fonte: PBS
Abstract
The establishment of the genetic code remains elusive nearly five decades after the code was elucidated. The stereochemical hypothesis postulates that the code developed from interactions between nucleotides and amino acids, yet supporting evidence in a biological context is lacking. We show here that anticodons are selectively enriched near their respective amino acids in the ribosome, and that such enrichment is significantly correlated with the canonical code over random codes. Ribosomal anticodon-amino acid enrichment further reveals that specific codons were reassigned during code evolution, and that the code evolved through a two-stage transition from ancient amino acids without anticodon interaction to newer additions with anticodon interaction. The ribosome thus serves as a molecular fossil, preserving biological evidence that anticodon-amino acid interactions shaped the evolution of the genetic code.
evolution of the genetic code stereochemical hypothesis anticodon-amino acid association
codon reassignment RNA-protein interaction
Footnotes
codon reassignment RNA-protein interaction
Footnotes
1To whom correspondence should be addressed. E-mail: lwang@salk.edu.
Author contributions: D.B.F.J. and L.W. designed research; D.B.F.J. performed research; D.B.F.J. and L.W. analyzed data; and D.B.F.J. and L.W. wrote the paper.
The authors declare no conflict of interest.
↵*This Direct Submission article had a prearranged editor.
This article contains supporting information online at www.pnas.org/cgi/content/full/1000704107/DCSupplemental.
+++++
PDF gratuito deste artigo aqui.
