Nucleic components

Zeatin 6-(4-hydroxy-3-methyl-but-(ranr-2-enyl)-aminopurine, a naturally occurring Cytokinin (see for formula). Z. occurs free in many plants, especially in immature maize kernels, and is identical with the previously described maize factor (MF). Its derivatives, Dihydrozeatin (see), Z. riboside and Z. ribotide are also cytokinins. The cis compound (see M-cu-y-Methyl-y-hydroxymethylallyladenosine) is a rare nucleic component in certain species of RNA. 

Very recently, we have developed and incorporated into the CHARMM molecular mechanics program a version of LN that uses direct-force evaluation, rather than linearization, for the fast-force components [91]. The scheme can be used in combination with SHAKE (e.g., for freezing bond lengths) and with periodic boundary conditions. Results for solvated protein and nucleic-... 

In 1971 the Protein Data Bank - PDB [146] (see Section 5.8 for a complete story and description) - was established at Brookhaven National Laboratories - BNL -as an archive for biological macromolccular cr7stal structures. This database moved in 1998 to the Research Collaboratory for Structural Bioinformatics -RCSB. A key component in the creation of such a public archive of information was the development of a method for effreient and uniform capture and curation of the data [147], The result of the effort was the PDB file format [53], which evolved over time through several different and non-uniform versions. Nevertheless, the PDB file format has become the standard representation for exchanging inacromolecular information derived from X-ray diffraction and NMR studies, primarily for proteins and nucleic acids. In 1998 the database was moved to the Research Collaboratory for Structural Bioinformatics - RCSB. 

A crystal is a solid with a periodic lattice of microscopic components. This arrangement of atoms is determined primarily by X-ray structure analysis. The smallest unit, called the unit cell, defines the complete crystal, including its symmetry. Characteristic crystallographic 3D structures are available in the fields of inorganic, organic, and organometallic compounds, macromolecules, such as proteins and nucleic adds. 

The Pullman method is a combination of the Del Re method for computing the a component of the charge and a semiempirical Hrickel calculation for the 7t portion. It has been fairly successful in describing dipole moments and atomic charges for nucleic acids and proteins. 

The major classes of organic compounds common to living systems are lipids pro terns nucleic acids and carbohydrates Carbohydrates are very familiar to us— we call many of them sugars They make up a substantial portion of the food we eat and provide most of the energy that keeps the human engine running Carbohy drates are structural components of the walls of plant cells and the wood of trees Genetic information is stored and transferred by way of nucleic acids specialized derivatives of carbohydrates which we 11 examine m more detail m Chapter 28... 

The most important derivatives of pyrimidines and purines are nucleosides Nucleosides are N glycosides m which a pyrimidine or purine nitrogen is bonded to the anomeric carbon of a carbohydrate The nucleosides listed m Table 28 2 are the mam building blocks of nucleic acids In RNA the carbohydrate component is d ribofuranose m DNA It IS 2 deoxy d ribofuranose... 

Table 28 2 doesn t include all of the nucleoside components of nucleic acids The presence of methyl groups on pyrimidine and purine rings is a common and often important variation on the general theme... 

Section 28 7 Nucleic acids are polynucleotides present m cells The carbohydrate component is D nbose m ribonucleic acid (RNA) and 2 deoxy d ribose m deoxyribonucleic acid (DNA)... 

Nucleic Acids. Phosphoms is an essential component of nucleic acids, polymers consisting of chains of nucleosides, a sugar plus a nitrogenous base, and joined by phosphate groups (43,44). In ribonucleic acid (RNA), the sugar is D-ribose in deoxyribonucleic acids (DNA), the sugar is 2-deoxy-D-ribose. 

Biopolymers are the naturally occurring macromolecular materials that are the components of all living systems. There are three principal categories of biopolymers, each of which is the topic of a separate article in the Eniyclopedia proteins (qv) nucleic acids (qv) and polysaccharides (see Carbohydrates Microbial polysaccharides). Biopolymers are formed through condensation of monomeric units ie, the corresponding monomers are amino acids (qv), nucleotides, and monosaccharides, for proteins, nucleic acids, and polysaccharides, respectively. The term biopolymers is also used to describe synthetic polymers prepared from the same or similar monomer units as are the natural molecules. 

Nucleic Acids. Nucleic acids are polynucleotides that is, they are condensation polymers of nucleotide monomers. A nucleotide is a three-component system, ie, a combination of a sugar, a phosphate, and a nitrogenous base residue. Adenosine monophosphate is an example ... 

The first dynamical simulation of a protein based on a detailed atomic model was reported in 1977. Since then, the uses of various theoretical and computational approaches have contributed tremendously to our understanding of complex biomolecular systems such as proteins, nucleic acids, and bilayer membranes. By providing detailed information on biomolecular systems that is often experimentally inaccessible, computational approaches based on detailed atomic models can help in the current efforts to understand the relationship of the strucmre of biomolecules to their function. For that reason, they are now considered to be an integrated and essential component of research in modern biology, biochemistry, and biophysics. 

Ruonne Substituted Analogs of Nucleic Acid Components Bergstrom, D E, Swartlmg, D J Mol Struct Energ S 250-306 133 o 2... 

The following biochemically related F-NMR studies ot structure or tunebon have been published nucleic acid components (mainly 5-fluorouracil) [86... 

FIGURE 1.25 The virus life cycle. Viruses are mobile bits of genetic iuformatiou encapsulated in a protein coat. The genetic material can be either DNA or RNA. Once this genetic material gains entry to its host cell, it takes over the host machinery for macromolecular synthesis and subverts it to the synthesis of viral-specific nucleic acids and proteins. These virus components are then assembled into mature virus particles that are released from the cell. Often, this parasitic cycle of virus infection leads to cell death and disease. 

Centrifugation can be used either as a preparative technique for separating and purifying macromolecules and cellular components or as an analytical technique to characterize the hydrodynamic properties of macromolecules such as proteins and nucleic acids. 

Nucleic acids have recently attracted the attention of very numerous laboratories. This is because nucleic acids belong to the most important components of living matter, for genetic traits are fixed in them and transmitted through them. Nucleic acids also play the main role during biosynthesis of specific proteins. 

As is well-known, nucleic acids consist of a polymeric chain of monotonously reiterating molecules of phosphoric acid and a sugar. In ribonucleic acid, the sugar component is represented by n-ribose, in deoxyribonucleic acid by D-2-deoxyribose. To this chain pyrimidine and purine derivatives are bound at the sugar moieties, these derivatives being conventionally, even if inaccurately, termed as pyrimidine and purine bases. The bases in question are uracil (in ribonucleic acids) or thymine (in deoxyribonucleic acids), cytosine, adenine, guanine, in some cases 5-methylcytosine and 5-hydroxymethylcyto-sine. In addition to these, a number of the so-called odd bases occurring in small amounts in some ribonucleic acid fractions have been isolated. 

The 8-aza analogs of purine bases were the first to be studied among all the aza analogs of nucleic acid bases (as early as 1945). Before that time the chemistry of these substances had not been treated in detail from any aspect. Thus the entire chemistry of the u-triazolo [4,5-d]pyrimidines was developed only in connection with the study of antimetabolites of nucleic acid components. Therefore all the papers involved are largely of preparative character and only rarely discuss. theoretical points. 

Dialdehyde-containing nucleic acids and their components, synthesis, properties, and affine modification of proteins 99UK267. 

Multidimensional separations allow for the analysis of complex mixtures, such as those from biological matrices with thousands of components that would be difficult or impossible to separate by utilizing only one method. Electrodriven separations have been employed to separate biological molecules for many years, due to the charged nature of amino acids and nucleic acids. The addition of an electrodriven component to a multidimensional separation is therefore desirable, especially for the separation of biological mixtures. 

In addition to the nucleic acids themselves, nucleic acid derivatives such as ATP are involved as phosphorylating agents in many biochemical pathways, and several important coenzymes, including NAD+, PAD, anti coenzvme A, have nucleic acid components. 

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