2-Aminoadenine is an adenine substituting for a base in S-2L cyanophage DNA

  title={2-Aminoadenine is an adenine substituting for a base in S-2L cyanophage DNA},
  author={M. D. Kirnos and Ivan Khudyakov and N. I. Alexandrushkina and Boris F. Vanyushin},
THE properties of DNA from viruses acting on blue-green algae (cyanophages) have been studied in only a few instances1,2. It is not known whether these DNA molecules contain any unusual bases3–7 or some modified (methylated) bases known to be present in DNA of many prokaryotes and to be specific for host modification and restriction phenomena. Here we report the isolation and identification of the base 2-aminoadenine and its deoxyribonucleoside from S-2L cyanophage DNA. Some unusual properties… 

Mechanisms supporting aminoadenine-based viral DNA genomes.

  • P. Kaminski
  • Biology, Chemistry
    Cellular and molecular life sciences : CMLS
  • 2021
The biosynthetic pathway for aminoadenine containing DNA as well as the exclusion of adenine are now elucidated and this example of a natural deviation from the genetic code provides a proof of concept for the synthetic biology of non-canonical nucleic acids.

Hypermodified bases in DNA

  • J. H.Gommers‐AmptP. Borst
  • Biology, Chemistry
    FASEB journal : official publication of the Federation of American Societies for Experimental Biology
  • 1995
This review gives an overview of the modified DNA bases identified thus far, with emphasis on the “very unusual” or hypermodified DNA bases.

How cyanophage S-2L rejects adenine and incorporates 2-aminoadenine to saturate hydrogen bonding in its DNA

It is shown that a nearby gene is a triphosphohydolase specific of dATP (DatZ), that leaves intact all other dNTPs, including dZTP, which explains the absence of A in S-2L genome.

Characterization of a triad of genes in cyanophage S-2L sufficient to replace adenine by 2-aminoadenine in bacterial DNA

It is determined that S-2L PurZ can use either dATP or ATP as a source of energy, thereby also depleting the pool of nucleotides in dATF and therefore opening the possibility to study synthetic organisms containing ZTGC-DNA.

A widespread pathway for substitution of adenine by diaminopurine in phage genomes

The Z genome endows phages with evolutionary advantages for evading the attack of host restriction enzymes, and the characterization of its biosynthetic pathway enables Z-DNA production on a large scale for a diverse range of applications.

Noncanonical DNA polymerization by aminoadenine-based siphoviruses

Congruent phylogenetic clustering of the polymerases and biosynthesis enzymes suggests that aminoadenine has propagated in DNA alongside adenine since archaic stages of evolution.

Structural dynamics and determinants of 2-aminoadenine specificity in DNA polymerase DpoZ of vibriophage (cid:2) VC8

Through mutagenesis and functional assays, it is suggested that the preference of (cid:2) VC8 DpoZ towards Z relies on a polymerase backtracking pro-cess, more efficient when the nascent base pair is A:T than when it is Z:T.

A ribozyme composed of only two different nucleotides

It is shown that binary informational macromolecules, containing only two different nucleotide subunits, can act as catalysts and that this ribozyme is specific for the formation of biologically relevant 3′,5′-phosphodiester linkages.

Identification and biosynthesis of thymidine hypermodifications in the genomic DNA of widespread bacterial viruses

Two thymidine hypermodifications are found and the discovery and characterization of two bases, 5-(2-aminoethoxy)methyluridine (5-NeOmdU) and 5-NedU, in the virion DNA of ViI and M6 phages, respectively, point to an unexplored diversity of DNA modifications and the underlying biochemistry of their formation.

The 5-chlorouracil:7-deazaadenine base pair as an alternative to the dT:dA base pair.

The search for its counterpart among different deoxyadenosine analogs showed that the stable duplex formation as well as the synthesis of long constructs, more than 2 kb, were successful with the 5-chloro-2'-deoxyuridine and 7-deaza-2-deoxy adenosine combination and with Taq DNA polymerase.



Replacement of Thymidylic Acid by Deoxyuridylic Acid in the Deoxyribonucleic Acid of a Transducing Phage for Bacillus subtilis

THE findings that the thermal denaturation temperature (Tm) of DNA from a wide variety of bacterial, plant and animal sources as well as the buoyant density in a cæsium chloride gradient are linearly

The interaction of actinomycin with DNA: requirement for the 2-amino group of purines.

A model for the structure of AM-DNA complexes which accounts for the participation of these functional groups has been proposed and it is proposed that AM is located in the minor groove of the DNA helix, where three hy-drogen bonds may be formed between the chromophore of the antibiotic and de-oxyguanosine in DNA.

Poly(2-aminoadenylic acid): interaction with poly(uridylic acid).

A method for establishing the combining ratios of polynucleotide complexes which used a computer to calculate the angles of intersection of mixing curves as explicit and continuous functions of the wavelength is described.