The origin of the organisation of the genetic code reflects both the biosynthetic relationships between amino acids and the physicochemical interactions between these and anticodons; moreover, these two forces do not act independently. It must therefore be explained why it is simultaneously true tha
On the Origin of the Genetic Code
β Scribed by Massimo Di Giulio
- Publisher
- Elsevier Science
- Year
- 1997
- Tongue
- English
- Weight
- 186 KB
- Volume
- 187
- Category
- Article
- ISSN
- 0022-5193
No coin nor oath required. For personal study only.
β¦ Synopsis
The main theories which have been suggested to explain the origin of genetic code organization are discussed. The coevolution theory, which considers the genetic code as a map of the biosynthetic relationships between amino acids, seems to be based on a mechanism that links it closely to certain stages of the origin of metabolism, which makes it preferable to other theories proposed as explanations of genetic code origin. Relationships, incompatibilities and compromises between the various theories are highlighted and these seem to indicate a certain lack of clarity in this field of research.
π SIMILAR VOLUMES
RNAs that catalyse their own aminoacylation have been recently selected in vitro. These findings support the notion that the primitive aminoacyl-tRNA synthetases may have been RNAs. In this paper, we propose a structural model for the first aminoacyl-tRNA synthetase consisting of an RNA complex form
Freeland et al. (Mol. Biol. Evol. 2000 a, 17, 511--518) have recently used a transformation of the PAM 74-100 matrix to study the level of optimization reached during genetic code origin. Since the PAM matrix counts the amino acid substitutions that occurred in families of homologous proteins during
L, length of protein; RBS, ribosome binding site; ribo-X, ribosome evolved to reduce premature termination; ribo-Q, ribosome further evolved to process quadruplet codons with high efficiency; S, Shannon entropy.
We argue that a primitive genetic code with only 20 separate words explains that there are 20 coded amino acids in modern life. The existence of 64 words on the modern genetic code requires modern life to read almost exclusively one strand of DNA in one direction. In our primitive code, both the ori
## Abstract The genetic code is nearly universal, and the arrangement of the codons in the standard codon table is highly nonrandom. The three main concepts on the origin and evolution of the code are the stereochemical theory, according to which codon assignments are dictated by physicochemical af