Secondary structure of DNA

In 1953, James Watson and Francis Crick made their classic proposal for the secondary structure of DNA. According to the Watson-Crick model, DNA under physiological conditions consists of two polynucleotide strands, running in opposite directions and coiled around each other in a double helix like the handrails on a spiral staircase. The two strands are complementary rather than identical and are held together by hydrogen bonds between specific pairs of... 

The secondary structure of DNA is shown in Figure B. This "double helix" model was first proposed in 1953 by James Watson and Francis Crick, who used the x-ray crystallographic data of Rosalind Franklin and Maurice Wilkins. Beyond that, they were intrigued by the results of analyses that showed that in DNA the ratio of adenine to thymine molecules is almost exactly 1 1, as is the ratio of cytosine to guanine ... 

Nucleic acid structures and sequences primary and secondary structure of DNA fragments, translocation of genes between two chromosomes, detection of nucleic acid hybridization, formation of hairpin structures (see Box 9.4), interaction with drugs, DNA triple helix, DNA-protein interaction, automated DNA sequencing, etc. 

The torsion angles around the bonds of the sugar-phosphate DNA backbone are of decisive importance for the secondary structure of DNA as well as for base-base recognition. [44] For antisense agents to be effective inhibitors of protein expression in vivo, they have to resist the action of DNA-degrading enzymes and bind to their... 

Secondary structure of DNA consists of two strands of polynucleotides coiled around each there in the form of double helix. The backbone of each strand is sugar-phosphate unit and the base unit of each strand are pointed into the interior of the helix and are linked through H-bonds. G and C are held by three H-bonds, A and T are held by two bonds. Unlike DNA, RNA has a single strand. 

In 1953, Watson and Crick proposed a three-dimensional structure of DNA which is a cornerstone in the history of biochemistry and molecular biology. The double helix they proposed for the secondary structure of DNA gained immediate acceptance, partly because it explained all known facts about DNA, and partly because it provided a beautiful model for DNA replication. 

Macromolecular Interactions and Their Biological Consequences 9.1. Influence of Tilorone Hydrochloride on the Secondary Structure of DNA... 

In addition, the subject of assembly looms as an apparently insurmountable obstacle. It is not at all clear how researchers would go about assembling individual molecular components into a functioning device, although bioengineering offers a potential solution to this problem. Examples of self-assembled structures exist everywhere in nature from the helical secondary structure of DNA to the human brain. Current knowledge of such systems is simply inadequate to allow scientists to employ similar forces to create synthetic molecular electronic devices. Clearly, an enormous amount of groundwork needs to be laid if the concept of the molecular electronic device or biochip computer is ever to become a reality. 

DNA The secondary structure of DNA consists of two polynucleotide chains wrapped around one another to form a double helix. The orientation of the helix is usually right handed witii the two chains running antiparallel to one another (Fig. 4.3). 

Similarly to proteins, both DNA and RNA have a secondary and a tertiary structure. The secondary structure of DNA shows two chains running in opposite directions, coiled in a left-handed (double) helix about the same axis. All the bases are inside the helix, and the sugar phosphate backbone is on the outside (see e.g. [1]). The chains are held together by hydrogen bonds between the bases with adenine always paired with thymine and guanine paired with cytosine. The base pairing in DNA is shown below ... 

The solution to this mystery lies in the secondary structure of DNA. 

Watson and Crick solved the secondary structure of DNA by building a model that fitted all the known experimental results. 

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