Deoxyribonucleic acid residues

For various reasons, the generalizations mentioned above must be regarded as strictly provisional. Analyses utilizing formic acid indicate the presence of more than one phosphorus atom per purine or pyrimidine residue. This discrepancy, it is pointed out, could equally well result from an apparent deficiency of bases, due to error in the analytical technique.160 It is also necessary to consider that some nucleic acids are now known to contain more bases than was previously realized. Thus, 5-(hydroxymethyl)-cytosine is present in various viruses,181-182 and 5-methylcytosine occurs in various animal and plant deoxyribonucleic acids but is absent from those of microbial origin.17-160-1M- 184- 186 Certain microbial deoxyribonucleic acids also contain 6-methylaminopurine.186a Various bacteriophage deoxyribonucleic acids have been found to contain a component which is believed to consist of a D-glucoside186b of 5 -(hydroxymethyl)cytidylic acid. 

The nucleic acids play a central role in the storage and expression of genetic information (see p. 236). They are divided into two major classes deoxyribonucleic acid (DNA) functions solely in information storage, while ribonucleic acids (RNAs) are involved in most steps of gene expression and protein biosynthesis. All nucleic acids are made up from nucleotide components, which in turn consist of a base, a sugar, and a phosphate residue. DNA and RNA differ from one another in the type of the sugar and in one of the bases that they contain. 

Polynucleotides consisting of ribonucleotide components are called ribonucleic acid (RNA), while those consisting of deoxyribonu-cleotide monomers are called deoxyribonucleic acid (DNA see p. 84). To describe the structure of polynucleotides, the abbreviations for the nucleoside components are written from left to right in the 5 - 3 direction. The position of the phosphate residue is also sometimes indicated by a p . In this way, the structure of the RNA segment shown Fig. 2 can be abbreviated as. .pUpG.. or simply as... 

Nucleic acids are of great interest because they are the units of heredity, the genes, and because they control the manufacture of proteins and the functions of the cells of living organisms. Hydrogen bonds play an important part in the novel structure proposed for deoxyribonucleic acid by Watson and Crick.1,5 This structure involves a detailed eomplement riness of two intertwined polynucleotide chains, which form a double helix.117 The complementariness in structure of the two chains was attributed by Watson and Crick to the formation of hydrogen bonds between a pyrimidine residue in one chain and a purine residue in the other, for each pair of nucleotides in the chains. 

Pyrimidine natural products are particularly important (Scheme lb). The nucleic acids contain pyrimidine and purine bases ribonucleic acids (RNA) contain D-ribose and uracil, deoxyribonucleic acids (DNA) contain 2-deoxy-D-ribose and thymine and both types contain phosphate residues,... 

An even more remarkable prediction was made by Crick and Watson (1953) of the structure of the vast molecules, such as that of deoxyribonucleic acid (DNA), which are concerned with the maintenance and transference of genetic information. These molecules contain very long chains of nucleotide units linked by covalency bonds. (A nucleotide consists of the residue of a sugar, often ribose or deoxyribose, one of a purine or pyrimidine base, and one of phosphoric acid, bonded together.) The Crick-Watson hypothesis was that the macromolecule consists of two such chains,... 

Figure 7.5 Example of a chimeric oligonucleic acid and its modification. Chimeric RNA-DNA hybrids are used for correction of point mutations in target genes. One strand of this oligonucleic acid is composed of O-methyl-RNA (outline) with an interruption of 5 bases of deoxyribonucleic acid. X and Y are target residues for correction. In the complementary strand, there is a DNA nick, and T residues loop both ends. 3 -exonuclease and FEN-1 may act on the nick, PARP-1 possibly binds to and is activated by the nick, resulting in activation of damage response pathways. In the modified version, the 3 end is replaced by ribonucleic acids. The 5 end is extended, and the flipped back RNA tail is added. Thus, the nick is expected to be resistant to 3 -exonuclease and FEN-1. In addition, PARP-1 may not be activated by such a nick.

Anti-deoxyribonucleic acid autoantibodies from human and mice suffering from Lupus erythematosus can penetrate into cells and accumulate in the cell nucleus. Based on the characteristics of a mi-ON A autoantibodies, VAYISRGGVSTYYSDTVKGRFTRQKYNKRA peptide (P3), which exhibits a-helix, has been used as a vector for the intracytoplasmic and intranuclear translocation of macromolecules (Table 16.7) (Avrameas et al., 1998, 1999). P3 shares similar capabilities with Antenapedia peptide (Derossi et al., 1994), but in contrast P3 operates only at 37 °C by an energy dependent mechanism. P3 linked to a 19 lysine residue sequence (K19-P3) forms complexes with plasmid DNA. Efficient transfection of mouse 3T3 cells and hamster lung CCL39 cells were obtained with these complexes. This transfection was not impaired by the presence of serum and did not require helper molecules such as chloroquine. These observations suggest that peptides from cell specific anti-DNA autoantibodies may represent a source of peptide-based gene delivery system with different specificities. 

Vanadium chloroperoxidase (C. inaequalis) is a 67,488 Da protein that comprises 609 amino acid residues, as determined from deoxyribonucleic acid (DNA) sequence analysis [20], As isolated, V-CIPO may contain a variable content of vanadium, depending on the concentration of vanadate in the growth medium however, one vanadium(V) per subunit can be achieved by addition of excess vanadate to the growth medium or to the purified protein [3,71] Like V-BrPO, V-CIPO is stable in the presence of organic substrates, to elevated temperatures, and to the presence of high concentrations of strong oxidants (e.g., HOC1) [59],... 

At a much later date, evidence supporting this assumption came from enzymic studies, which indicated that the deoxypentosyl residues of all nucleosides of deoxyribonucleic acids are similar. Manson and Lampen67 demonstrated that deoxyinosine (IX)68 69 can be synthesized from thy-... 

It was concluded39 from these studies that the two nucleotides obtained by enzymic hydrolysis of the deoxyribonucleic acid of T2 bacteriophage are 2-deoxy-5 -(hydroxymethyl)cytidylic acid and a glucose derivative thereof. It was also concluded that the glucose residue is affixed to the pyrimidine portion of the nucleotide and nucleoside of 5-(hydroxymethyl)-cytosine and, on the basis of the near identity of the spectra of the two nucleotides of 5-(hydroxymethyl)cytosine, it was suggested that the hexose is attached to the hydroxymethyl group of the pyrimidine. 

Deoxyribonucleic acid is the genetic material such that the information to make all the functional macromolecules of the cell is preserved in DNA (Sinden, 1994). Ribonucleic acids occur in three functionally different classes messenger RNA (mRNA), ribosomal RNA (rRNA), and transfer RNA (tRNA) (Simons and Grun-berg-Manago, 1997). Messenger RNA serves to carry the information encoded from DNA to the sites of protein synthesis in the cell where this information is translated into a polypeptide sequence. Ribosomal RNA is the component of ribosome which serves as the site of protein synthesis. Transfer RNA (tRNA) serves as a carrier of amino acid residues for protein synthesis. Amino acids are attached as aminoacyl esters to the 3 -termini of the tRNA to form aminoacyl-tRNA, which is the substrate for protein biosynthesis. 

Crick (1954) proposed a two-stranded helix, somewhat reminiscent of the Watson-Crick double-strand helix which had been so successful for deoxyribonucleic acid. The model consisted of two polypeptide chains wound helically around a common axis and held together by interchain peptide hydrogen bonds. The peptide bonds were all in the cfs-configuration, and the repeating unit consisted of a pair of amino acid residues, one perpendicular and the other parallel to the fiber axis. As a result, planes... 

The chemistry of tuberculinic acid (the nucleic acid of the tubercle bacillus) was investigated by Brown and Johnson. The acid was purified by conversion to the copper salt. Distillation with hydrochloric acid yielded small amounts of furfural, indicating the presence of only a trace of pentose in the residue. Levulinic acid was identified, and it was thought on this evidence that the sugar associated with the acid was a hexose. Tuberculinic acid is unique in that it does not contain uracil, has a low pentose content and contains an unusual pyrimidine derivative. The tuberculinic acid was considered to be more nearly related to deoxyribonucleic acid than to ribonucleic acid. ... 

In deoxyribonucleic acid (DNA) the carbohydrate is 2-deoxy-D-ribose, while in ribonucleic acid (RNA) the carbohydrate residue is ribose. Three types of RNA were recognized, and they can be messenger RNA (mRNA), transfer RNA (tRNA), or ribosomal RNA (rRNA), which is the most abundant in cells. Values between 10 and 10 Dalton have been reported for the molecular weight of DNA, and the molecular weight is about 10 for rRNA, 10 for mRNA, and lOMor rRNA. The simplified structures of DNA and RNA are the following ... 

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