Hachimoji DNA
Hachimoji DNA (fra japansk 八文字 hachimoji = otte bogstaver) er et syntetisk DNA, der ud over de fire naturlige nukleinbaser i DNA (nemlig A, T, G og C) bruger yderligere fire syntetiske baser: P, Z, B og S.
Den genetiske kode kan dermed fordobles til en “syntetisk” kode med otte bogstaver. Det nye syntetiske DNA har således fire forskellige basepar, to nye syntetiske basepar, PZ og BS, dannet af de nye syntetiske baser ud over de to normale par, AT og GC (se skemaerne).
Forsøg med det nye syntetiske DNA har vist at det kan transkripteres til hachimojo RNA med en modificeret polymerase, hvorved der kunne produceres en type katalytisk RNA (ribozym eller aptamer).
Fordelene ved en udvidet DNA-kode kunne omfatte lagring af stærkt komprimerede data, dvs. en forbedret genetisk kode, samt indsigt i livets generelle kemiske forudsætninger dvs. hvad man også kunne forvente af eventuelt udenjordisk liv. [1][2][3][4][5]
En anden fordel kunne være ved udvikling af nye lægemidler.[6]
Base Kemisk navn Kemisk formel SMILES Kemisk struktur ChemSpider PubChem P 2-Aminoimidazo[1,2a][1,3,5]triazin-4(1H)-one 2-amino-8-(1′-b-D-2′-deoxyribofuranosyl)-imidazo-[1,2a]-1,3,5-triazin-[8H]-4-one[1]
C5H5N5O C1=CN2C(=O)NC(=NC2=N1)N 
10205066 135600909 Z 6-Amino-5-nitropyridin-2-ol 6-amino-3-(1′-b-D-2′-deoxyribofuranosyl)-5-nitro-1H-pyridin-2-one[1]
C5H5N3O3 C1=CC(=O)NC(=C1[N+](=O)[O-])N 
9357814 11182729 B Isoguanine 6-amino-9[(1′-b-D-2′-deoxyribofuranosyl)-4-hydroxy-5-(hydroxymethyl)-oxolan-2-yl]-1H-purin-2-one[1]
C5H5N5O C1=NC2=NC(=O)NC(=C2N1)N 
69351 76900 S rS Isocytosine C4H5N3O C1=CN=C(NC1=O)N 
60309 66950 dS 1-Methylcytosine 3-methyl-6-amino-5-(1′-b-D-2′-deoxyribofuranosyl)-pyrimidin-2-one[1]
C5H7N3O CN1C=CC(=NC1=O)N 
71474 79143
Til venstre hachimoji DNA (dR = deoxyribose).
Til højre hachimoji RNA (R = ribose).
De naturlige baser er øverst.
De unaturlige syntetiske baser er nederst.
Hydrogenbindinger er stiplede grønne linier med acceptoratomet i rødt[1]
Henvisninger
- ^ a b c d e f Hoshika S, Leal NA, Kim MJ, Kim MS, Karalkar NB, Kim HJ, et al. (februar 2019). "Hachimoji DNA and RNA: A genetic system with eight building blocks". Science. 363 (6429): 884-887. doi:10.1126/science.aat0971. PMID 30792304.
- ^ American Association for the Advancement of Science (21. februar 2019). "Hachimoji – Expanding the genetic alphabet from four to eight". EurekAlert!. Hentet 22. februar 2019.
- ^ Brown D, Landau E (21. februar 2019). "Research creates DNA-like molecule to aid search for alien life". Phys.org. Hentet 22. februar 2019.
- ^ Dumé B (22. februar 2019). "Hachimoji DNA doubles the genetic code". Physics World. Hentet 22. februar 2019.
- ^ Zimmer C (21. februar 2019). "DNA Gets a New — and Bigger — Genetic Alphabet - DNA is spelled out with four letters, or bases. Researchers have now built a system with eight. It may hold clues to the potential for life elsewhere in the universe and could also expand our capacity to store digital data on Earth". The New York Times. Hentet 21. februar 2019.
- ^ A semi-synthetic organism that stores and retrieves increased genetic information. Nature 2019
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6-Amino-5-nitropyridin-2-one structure
Animation of a rotating DNA structure
- //www.bernstein-plus-sons.com/software/rasmol/ RasMol 2.7.2.1.1] using the 1BNA.pdb dataset and the following commands:
GUI options were: Options->Specular, Display->Sticks
Then, in the command line:
write frame-000.gif set write true script script.txt
where script.txt was a separate text file in the same directory, consisting of the same two repeating lines:
rotate x 03 write frame-001.gif rotate x 03 write frame-002.gif rotate x 03 write frame-003.gif ...
from 001 up to 119 (for a total of 120 images when combined with frame-000.gif).
This was then loaded in Adobe ImageReady, and saved as an animated GIF.
chemical structure of isocytosine
Forfatter/Opretter: WolfmanSF, Licens: CC BY-SA 4.0
Uploader's notes: The PNG versions of the image do NOT display correctly at reduced scales (in terms of the nitro substiuent).
Hachimoji RNA hydrogen bonds are depicted as dashed green lines, with acceptor atoms shown in red. Nucleobase Z is 6-amino-5-nitropyridin-2-ol, P is 5-aza-7-deazaguanine, S in rS is isocytosine and B is isoguanine.
Forfatter/Opretter: WolfmanSF, Licens: CC BY-SA 4.0
Uploader's notes: The PNG versions of the image do NOT display correctly (in terms of the methyl and nitro substiuents).
Hachimoji DNA hydrogen bonds are depicted as dashed green lines, with acceptor atoms shown in red. Nucleobase Z is 6-amino-5-nitropyridin-2-ol, P is 5-aza-7-deazaguanine, S in dS is 1-methylcytosine and B is isoguanine.
