The Preparation and Properties of Some Covalently Bonded Purine-Pyrimidine Base Pairs

1968 ◽  
Vol 6 (2) ◽  
pp. 131-136 ◽  
Author(s):  
Ch. Lachman ◽  
S. Cohen
Keyword(s):  
Base Pairs ◽  
Pyrimidine Base ◽  
Covalently Bonded ◽  
Purine Pyrimidine

scholarly journals Parallel-stranded duplex DNA containing blocks of trans purine-purine and purine-pyrimidine base pairs

1994 ◽  
Vol 22 (16) ◽  
pp. 3293-3303 ◽  
Author(s):  
Elisabeth M. Evertsz ◽  
Karsten Rippe ◽  
Thomas M. Jovin
Keyword(s):  
Duplex Dna ◽  
Base Pairs ◽  
Pyrimidine Base ◽  
Purine Pyrimidine

scholarly journals Abiotic synthesis of purine and pyrimidine ribonucleosides in aqueous microdroplets

2017 ◽  
Vol 115 (1) ◽  
pp. 36-40 ◽  
Author(s):  
Inho Nam ◽  
Hong Gil Nam ◽  
Richard N. Zare
Keyword(s):  
Aqueous Solution ◽  
Mass Spectra ◽  
Room Temperature ◽  
Flight Time ◽  
Magnesium Ion ◽  
Base Pairs ◽  
Pyrimidine Base ◽  
Mild Conditions ◽  
Letter Alphabet ◽  
Purine Pyrimidine

Aqueous microdroplets (<1.3 µm in diameter on average) containing 15 mM d-ribose, 15 mM phosphoric acid, and 5 mM of a nucleobase (uracil, adenine, cytosine, or hypoxanthine) are electrosprayed from a capillary at +5 kV into a mass spectrometer at room temperature and 1 atm pressure with 3 mM divalent magnesium ion (Mg2+) as a catalyst. Mass spectra show the formation of ribonucleosides that comprise a four-letter alphabet of RNA with a yield of 2.5% of uridine (U), 2.5% of adenosine (A), 0.7% of cytidine (C), and 1.7% of inosine (I) during the flight time of ∼50 µs. In the case of uridine, no catalyst is required. An aqueous solution containing guanine cannot be generated under the same conditions given the extreme insolubility of guanine in water. However, inosine can base pair with cytidine and thus substitute for guanosine. Thus, a full set of ribonucleosides to generate the purine–pyrimidine base pairs A-U and I-C are spontaneously generated in aqueous microdroplets under similar mild conditions.

Genetic transcription

1966 ◽  
Vol 164 (995) ◽  
pp. 181-197 ◽  
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Messenger Rna ◽  
Cellular Protein ◽  
Base Sequence ◽  
Structural Members ◽  
Base Pairs ◽  
Pyrimidine Base ◽  
Form Part

The purine and pyrimidine base sequence of DNA , permanent repository of the genetic information, must be transcribed on to ribopolynucleotides before genotype can be translated into phenotype. This transcription gives rise to three recognizably different classes of RNA molecules: (1) two species of ribosomal RNA , one about 1500 and the other 3000 nucleotides in length, that form part of the structural members of the engine for cellular protein synthesis; (2) several dozen species of transfer RNA , each about 100 nucleotides in length, that provide adaptors in protein synthesis for the twenty ‘standard’ amino acids; and (3) hundreds, or thousands, of species of messenger RNA , probably of variable length, but reaching into the tens of thousands of nucleotides, that furnish the templates for orderly copolymerization of amino acids into specific polypeptides. To the particular purine and pyrimidine base sequence of every one of these multifarious RNA species there corresponds some homologous sector of the DNA where this sequence recurs in one of the complementary deoxypolynucleotide strands. It is generally assumed that the DNA strand of base sequence complementary to that of the RNA transcript acts as the template in transcription, because, in analogy with the mechanism of DNA replication, one imagines that formation of the complementary base pairs (Watson & Crick 1953) is responsible for specific alinement of the ribonucleotide monomers. But this point has not yet been firmly established, at least for the actual in vivo transcription. It would be prudent, therefore, to keep in mind for the time being that for transcription some other basepairing mechanism might conceivably obtain. For instance, pairing might also involve identical, rather than complementary, bases (Donohue & Stent 1956), in which case the DNA strand of identical base sequence could act as transcription template, or pairing might involve base triplets, rather than pairs (Stent 1958), in which case both DNA strands of the homologous sector could act jointly as transcription template.

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