scholarly journals Optimal Evolution of the Standard Genetic Code

Author(s):  
Michael Yarus

The Standard Genetic Code (SGC) exists in every organism known on Earth. SGC evolution via early unique codon assignment, then later wobble, yields coding resembling the near-universal code. Below, later wobble also creates an optimal route to accurate codon assignment. This assignment time matches a previous mean time for ordered codes, exhibiting ≥ 90% of SGC order. Accurate evolution is also accessible, sufficiently frequent to appear in populations of 103 to 104 codes. SGC-like coding capacity, code order and assignments therefore arise together, in one attainable evolutionary intermediate. Examples, which plausibly resemble coding at evolutionary domain separation, are characterized.

2021 ◽  
Vol 89 (1-2) ◽  
pp. 45-49
Author(s):  
Michael Yarus

AbstractThe Standard Genetic Code (SGC) exists in every known organism on Earth. SGC evolution via early unique codon assignment, then later wobble, yields coding resembling the near-universal code. Below, later wobble is shown to also create an optimal route to accurate codon assignment. Time of optimal codon assignment matches the previously defined mean time for ordered coding, exhibiting ≥ 90% of SGC order. Accurate evolution is also accessible, sufficiently frequent to appear in populations of 103 to 104 codes. SGC-like coding capacity, code order, and accurate assignments therefore arise together, in one attainable evolutionary intermediate. Examples, which plausibly resemble coding at evolutionary domain separation, are characterized.


2020 ◽  
Author(s):  
Kuba Nowak ◽  
Paweł Błażej ◽  
Małgorzata Wnetrzak ◽  
Dorota Mackiewicz ◽  
Paweł Mackiewicz

1AbstractReprogramming of the standard genetic code in order to include non-canonical amino acids (ncAAs) opens a new perspective in medicine, industry and biotechnology. There are several methods of engineering the code, which allow us for storing new genetic information in DNA sequences and transmitting it into the protein world. Here, we investigate the problem of optimal genetic code extension from theoretical perspective. We assume that the new coding system should encode both canonical and new ncAAs using 64 classical codons. What is more, the extended genetic code should be robust to point nucleotide mutation and minimize the possibility of reversion from new to old information. In order to do so, we follow graph theory to study the properties of optimal codon sets, which can encode 20 canonical amino acids and stop coding signal. Finally, we describe the set of vacant codons that could be assigned to new amino acids. Moreover, we discuss the optimal number of the newly incorporated ncAAs and also the optimal size of codon blocks that are assigned to ncAAs.


PLoS ONE ◽  
2018 ◽  
Vol 13 (10) ◽  
pp. e0205450 ◽  
Author(s):  
Paweł Błażej ◽  
Małgorzata Wnętrzak ◽  
Dorota Mackiewicz ◽  
Paweł Mackiewicz

PLoS ONE ◽  
2018 ◽  
Vol 13 (8) ◽  
pp. e0201715 ◽  
Author(s):  
Paweł Błażej ◽  
Małgorzata Wnętrzak ◽  
Dorota Mackiewicz ◽  
Paweł Mackiewicz

Life ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1338
Author(s):  
Elena Fimmel ◽  
Markus Gumbel ◽  
Martin Starman ◽  
Lutz Strüngmann

It is believed that the codon–amino acid assignments of the standard genetic code (SGC) help to minimize the negative effects caused by point mutations. All possible point mutations of the genetic code can be represented as a weighted graph with weights that correspond to the probabilities of these mutations. The robustness of a code against point mutations can be described then by means of the so-called conductance measure. This paper quantifies the wobble effect, which was investigated previously by applying the weighted graph approach, and seeks optimal weights using an evolutionary optimization algorithm to maximize the code’s robustness. One result of our study is that the robustness of the genetic code is least influenced by mutations in the third position—like with the wobble effect. Moreover, the results clearly demonstrate that point mutations in the first, and even more importantly, in the second base of a codon have a very large influence on the robustness of the genetic code. These results were compared to single nucleotide variants (SNV) in coding sequences which support our findings. Additionally, it was analyzed which structure of a genetic code evolves from random code tables when the robustness is maximized. Our calculations show that the resulting code tables are very close to the standard genetic code. In conclusion, the results illustrate that the robustness against point mutations seems to be an important factor in the evolution of the standard genetic code.


2017 ◽  
Author(s):  
Miloje M. Rakocevic

In previous two works [1], [2] we have shown the determination of genetic code by golden and harmonic mean within standard Genetic Code Table, i.e. nucleotide triplet table, whereas in this paper we show the same determination through a specific connection between two tables – of nucleotide doublets Table and triplets Table, over polarity of amino acids, measured by Cloister energy.


2020 ◽  
Author(s):  
Michael Yarus

AbstractA near-universal Standard Genetic Code (SGC) implies a single origin for Earthly life. To study this unique event, I compute paths to the SGC, comparing different plausible histories. Notably, SGC-like coding emerges from traditional evolutionary mechanisms, and a superior path can be identified.To objectively measure evolution, progress values from 0 (random coding) to 1 (SGC-like) are defined: these measure fractions of random-code-to-SGC distance. Progress types are spacing/distance/delta Polar Requirement, detecting space between identical assignments /mutational distance to the SGC/chemical order, respectively. A coding system was based on known RNAs performing aminoacyl-RNA synthetase reactions. Acceptor RNAs exhibit SGC-like wobble; alternatively, non-wobbling triplets uniquely encode 20 amino acids/start/stop. Triplets acquire 22 functions by stereochemistry, selection, coevolution, or randomly. Assignments also propagate to an assigned triplet’s neighborhood via single mutations, but can also decay.Futile evolutionary paths are plentiful due to the vast code universe. Thus SGC evolution is critically sensitive to disorder from random assignments. Evolution also inevitably slows near coding completion. Coding likely avoided these difficulties, and two suitable paths are compared. In late wobble, a majority of non-wobble assignments are made before wobble is adopted. In continuous wobble, a uniquely advantageous early intermediate supplies the gateway to an ordered SGC. Revised coding evolution (limited randomness, late wobble, concentration on amino acid encoding, chemically conservative coevolution with a chemically-ordered elite) produces varied full codes with excellent joint progress values. A population of only 600 independent coding tables includes SGC-like members; a Bayesian path toward more accurate SGC evolution is available.


2016 ◽  
Vol 14 (3) ◽  
pp. 275-298 ◽  
Author(s):  
Natasa Misic

This paper represents the preliminary results and conclusions on the one of fundamental questions of the genetic code related to the underlying selective mechanisms involved in its origin and evolution, in particular their hypothetical different nature, originally considered in [1,2,3]. A novel approach is introduced, based on known arithmetic regularities inside the genetic code, determined by the nucleon balances of amino acids and their divisibility by the decimal number 37 [4]. As a parameter of the genetic code systematization is introduced an aggregate nucleon number of amino acid and cognate codon, while divisibility test is carried out not only by the number 37, but also by 13.7, the selfsimilarity constant of decimal scaling [5]. Relevant nucleon sums were obtained for the most prominent divisions of the standard genetic code (SGC) according to p-adic model of the vertebrate mitochondrial code (VMC) in [6]. The nucleon number divisibility pattern of 37 and 13.7 for the RNA and DNA codon space, as well as for the amino acid space is also analyzed. The obtained results, particularly a general higher divisibility of the nucleon sums by the numbers 37 and 13.7 in SGC than in VMC, as well as a correspondence between the nucleon number divisibility pattern of both the RNA codon space and the amino acid space of SGC, how separately so conjointly, with the code degeneracy pattern, suggest some conclusions: support the hypothesis [1,2,3,7] that the selective driving forces acting during an emergence (an ancient phase) and an evolution (a modern phase) of the genetic code are different, imply the existence of an environmental-dependent stereochemical mechanism throughout the entire period of the genetic code emergence and support a mineral-mediated origin of the genetic code [7,8].


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