Experiments are reported which demonstrate that the photoalkylation reaction is dependent upon secondary structural alterations in DNA. It is suggested that the photoalkylation of purines proceeds through free-radical intermediates.R.DepartmentBEN-ISHAI...
It is known that alkylated DNA spontaneously loses alkylated purinesand that the apurinic sites are quickly hydrolysed in an alkaline solution. Figure 2 shows that the action of the purified bacterial enzyme on alkylated DNA is restricted to the apurinic sites resulting from the depurination ...
The ability to perform de novo biosynthesis of purines is present in organisms in all three domains of life, reflecting the essentiality of these molecules to life. Although the pathway is quite similar in eukaryotes and bacteria, the archaeal pathway is
Purines are essential components of the DNA and RNA nucleobase backbone and also function as components of other metabolic molecules that are involved in a great number of metabolic pathways, such as adenosine triphosphate (ATP), cyclic adenosine monophosphate (cAMP), reduced nicotinamide adenine dinuc...
What is the significance of the 5' and 3' positions in the deoxyribose sugar of DNA? Why is double-stranded RNA more stable than DNA? Why are purines used as energy currency? Why the nitrogenous bases of DNA are approximately perpendicular to the axis of the molecule?
Name the four RNA bases. Name the three DNA Sequence Databases and where they are located. List all of the bases of deoxyribonucleic acid (DNA) that are purines. List the nitrogen bases found in DNA. What are the four bases of RNA? Which bases are found in DNA and RNA? What are the...
- In RNA, the sugar is ribose. 4. Types of Nitrogenous Bases: There are two categories of nitrogenous bases: - Purines: Adenine (A) and Guanine (G) are present in both RNA and DNA. - Pyrimidines: This group includes Cytosine (C), Thymine (T), and Uracil (U). 5. Comparing Bases...
Postmortem change of purine bases Aside from the crucial roles of purines (adenine and guanine) in DNA and RNA, purines are also significant components in a number of other important biomolecules, such as ATP, GTP, cyclic AMP, and coenzyme A. These substances may undergo chemical reactions af...
There are two groups of bases: Pyrimidines: Cytosine and Thymine each have a single six-member ring. Purines: Guanine and Adenine each have a double ring made up of a five-atom ring attached by one side to a six-atom ring. The order of nucleotides along DNA polymers encodes the ...
Purines are also required for the development and maintenance of mature T lymphocytes. Defects in critical genes in the purine synthesis pathway, including Ada and Pnp, cause severe immunodeficiency (Arpaia et al., 2000, Markert, 1991, Stoop et al., 1977). However, the major source of ...