On the enzymatic incorporation of an imidazole nucleotide into DNA

2017 ◽  
Vol 15 (20) ◽  
pp. 4449-4455 ◽  
Author(s):  
Pascal Röthlisberger ◽  
Fabienne Levi-Acobas ◽  
Ivo Sarac ◽  
Philippe Marlière ◽  
Piet Herdewijn ◽  
...  

We have evaluated the possibility for using an imidazole modified nucleoside triphosphate for the enzymatic construction of artificial metal base pair with view on an expansion of the genetic code.

2019 ◽  
Author(s):  
Marie Flamme ◽  
Pascal Röthlisberger ◽  
Fabienne Levi-Acobas ◽  
Mohit Chawla ◽  
Romina Oliva ◽  
...  

The expansion of the genetic alphabet with additional, unnatural base pairs (UBPs) is an important and long standing goal in synthetic biology. Nucleotides acting as ligands for the coordination of metal cations have advanced as promising candidates for such an expansion of the genetic alphabet. However,the inclusion of artificial metal base pairs in nucleic acids mainly relies on solid-phase synthesis approaches and very little is known on polymerase-mediated synthesis. Herein, we report on the selective and high yielding enzymatic construction of a silver-mediated base pair as well as a two-step protocol for the synthesis of DNA duplexes containing a metal UBP. Guided by DFT calculations, we also shed light into the mechanism of formation of this UBP as well as into the structural and energetic preferences. Even though this silver UBP is not directly amenable to in vitro selection experiments, the enzymatic synthesis of this UBP provides valuable insights for the design of future, more potent systems aiming at expanding the genetic alphabet. <br>


2019 ◽  
Author(s):  
Marie Flamme ◽  
Pascal Röthlisberger ◽  
Fabienne Levi-Acobas ◽  
Mohit Chawla ◽  
Romina Oliva ◽  
...  

The expansion of the genetic alphabet with additional, unnatural base pairs (UBPs) is an important and long standing goal in synthetic biology. Nucleotides acting as ligands for the coordination of metal cations have advanced as promising candidates for such an expansion of the genetic alphabet. However,the inclusion of artificial metal base pairs in nucleic acids mainly relies on solid-phase synthesis approaches and very little is known on polymerase-mediated synthesis. Herein, we report on the selective and high yielding enzymatic construction of a silver-mediated base pair as well as a two-step protocol for the synthesis of DNA duplexes containing a metal UBP. Guided by DFT calculations, we also shed light into the mechanism of formation of this UBP as well as into the structural and energetic preferences. Even though this silver UBP is not directly amenable to in vitro selection experiments, the enzymatic synthesis of this UBP provides valuable insights for the design of future, more potent systems aiming at expanding the genetic alphabet. <br>


2000 ◽  
Vol 189 (2) ◽  
pp. 91-95 ◽  
Author(s):  
Renate Mentel ◽  
Stefan Kurek ◽  
Ursula Wegner ◽  
Martin v. Janta-Lipinski ◽  
Lutz Gürtler ◽  
...  

2017 ◽  
Vol 114 (6) ◽  
pp. 1317-1322 ◽  
Author(s):  
Yorke Zhang ◽  
Brian M. Lamb ◽  
Aaron W. Feldman ◽  
Anne Xiaozhou Zhou ◽  
Thomas Lavergne ◽  
...  

All natural organisms store genetic information in a four-letter, two-base-pair genetic alphabet. The expansion of the genetic alphabet with two synthetic unnatural nucleotides that selectively pair to form an unnatural base pair (UBP) would increase the information storage potential of DNA, and semisynthetic organisms (SSOs) that stably harbor this expanded alphabet would thereby have the potential to store and retrieve increased information. Toward this goal, we previously reported thatEscherichia coligrown in the presence of the unnatural nucleoside triphosphates dNaMTP and d5SICSTP, and provided with the means to import them via expression of a plasmid-borne nucleoside triphosphate transporter, replicates DNA containing a single dNaM-d5SICS UBP. Although this represented an important proof-of-concept, the nascent SSO grew poorly and, more problematically, required growth under controlled conditions and even then was unable to indefinitely store the unnatural information, which is clearly a prerequisite for true semisynthetic life. Here, to fortify and vivify the nascent SSO, we engineered the transporter, used a more chemically optimized UBP, and harnessed the power of the bacterial immune response by using Cas9 to eliminate DNA that had lost the UBP. The optimized SSO grows robustly, constitutively imports the unnatural triphosphates, and is able to indefinitely retain multiple UBPs in virtually any sequence context. This SSO is thus a form of life that can stably store genetic information using a six-letter, three-base-pair alphabet.


2021 ◽  
Vol 9 (12) ◽  
Author(s):  
Åsa Wohlin

The search for regularities in the background for the genetic code and its codon assignments is here further developed, earlier shown to have many correlations with numeral series of integers 5 →0 with different exponents. The atomic mass analysis here counts on 20 + 4 double-coded amino acids, here including Ile AUA as such. A central finding here is that the C-skeleton seems to build on an hierarchical development of the mentioned basic series giving top numbers equal to those returning in side-chain divisions and on first three levels those of C-atoms in base-pair domains. It can very elementary explain the 3/2-division in the weight series. A few main results from earlier articles are shortly recapitulated, since it’s shown here that an x­3-series times 15 (x = integers 5 → 0) joins those earlier aspects and add new ones. It’s found also that atoms with valences 4 + 3 relative those with 2 + 1 make up a 3 to 1-division in both base-pair groups of codon domains, strengthening the earlier observation of valences as one important guiding principle in the relation between codons and domains of amino acids; valences of the atoms which in themselves make up a basic series 5 → 0 in the code when phosphorus P is included. Finally, fundamental factors in the code are gathered, where step 4 →3 seems reign at bottom of the code and number 7, exactly mean value of all atoms.


2020 ◽  
Vol 15 (11) ◽  
pp. 2872-2884
Author(s):  
Marie Flamme ◽  
Pascal Röthlisberger ◽  
Fabienne Levi-Acobas ◽  
Mohit Chawla ◽  
Romina Oliva ◽  
...  

RNA ◽  
2008 ◽  
Vol 14 (7) ◽  
pp. 1264-1269 ◽  
Author(s):  
J. Lehmann ◽  
A. Libchaber
Keyword(s):  

2004 ◽  
Vol 126 (41) ◽  
pp. 13298-13305 ◽  
Author(s):  
Ichiro Hirao ◽  
Yoko Harada ◽  
Michiko Kimoto ◽  
Tsuneo Mitsui ◽  
Tsuyoshi Fujiwara ◽  
...  
Keyword(s):  

2021 ◽  
Author(s):  
Jean Lehmann ◽  
Shixin Ye

The degeneracy of the genetic code confers a wide array of properties to coding sequences. Yet, its origin is still unclear. A structural analysis has shown that the stability of the Watson-Crick base pair at the second position of the anticodon-codon interaction is a critical parameter controlling the extent of non-specific pairings accepted at the third position by the ribosome, a flexibility at the root of degeneracy. Based on recent cryo-EM analyses, the present work shows that residue A1493 of the decoding center provides a significant contribution to the stability of this base pair, revealing that the ribosome is directly involved in the establishment of degeneracy. Building on existing evolutionary models, we show the evidence that the early appearance of A1493 and A1492 established the basis of degeneracy when an elementary kinetic scheme of translation was prevailing. Logical considerations on the expansion of this kinetic scheme indicate that the acquisition of the peptidyl transferase center was the next major evolutionary step, while the induced-fit mechanism, that enables a sharp selection of the tRNAs, necessarily arose later when G530 was acquired by the decoding center.


Sign in / Sign up

Export Citation Format

Share Document