Nucleotide structure-function relationship

A cloned complementary DNA to a neurotoxin precursor RNA extracted from the venom glands of Laticauda semifasciata was isolated and its nucleotide sequence was identified 11). The cloning of neurotoxin should aid the understanding of structure—function relationship eventually. 

C3 cleavage is a selective and particularly efficient tool for examining structure-function relationships of the second cytoplasmic domain. Binding affinities for ADP and ATP are reduced 4-5-fold, while TNP-ATP binds with the same affinity as in native Na,K-ATPase. Nucleotide binding is not affected by or Rb although... 

Hofmann F, Biel M, Kaupp UB (2005) International Union of Pharmacology. LI. Nomenclature and structure-function relationships of cyclic nucleotide-regulated channels. Pharmacol Rev 57 455-62... 

Perlow-Poehnelt, R.A., Likhterov, I., Sdcchitano, D.A., Geacintov, N.E., and Broyde, S. (2004) The spadous active site of a Y -family DNA polymerase fadlitates promiscuous nucleotide incorporation opposite a bulky cardnogen-DNA addud eluddating the structure-function relationship through experimental and computational approaches. 

My close friendship with Charles Yanofsky and the times we spent together revealed to me the power of genetics for probing structure-function relationships of enzymes. Consequently, Bill Folk, Maurizio laccarino and I examined mutational alterations affecting amino acyl tRNA synthetases and John Carbon, Charles Hill, Larry Soli, Folk and Moshe Yaniv studied genetically altered tRNA " " the latter investigations proved to be the most productive because they showed that changes in nucleotide sequences of tRNA could affect the specificity of amino acylation and the translation of codons in mRNA. ... 

Biological information is stored in the nucleotide base structure of DNA. By manipulating the structure of DNA it is possible to improve and understand the structure and functional relationships of catalysts (termed protein engineering). Considerable improvements have been made to products derived from enzyme systems, both in the quality and amount of metabolites, enzymes and proteins produced by organisms (often termed genetic engineering). 

Jeffrey GA (1989) Hydrogen bonding in crystal structures of nucleic acid components purines, pyrimidines, nucleosides and nucleotides. In Saenger W (ed), Landolt-BOrnstein. Numerical Data and Functional Relationships in Science and Technology. New Series, Group VII, Vol. Ib. Springer, Berlin, pp 277-348... 

An important question arises about the effects of phospholipid composition and the function of membrane-bound enzymes. The phospholipid composition and cholesterol content in cell membranes of cultured cells can be modified, either by supplementing the medium with specific lipids or by incubation with different types of liposomes. Direct effects of phospholipid structure have been observed on the activity of the Ca2+-ATPase (due to changes in the phosphorylation and nucleotide binding domains) [37]. Evidence of a relationship between lipid structure and membrane functions also comes from studies with the insulin receptor [38]. Lipid alteration had no influence on insulin binding, but modified the kinetics of receptor autophosphorylation. 

As shown in Fig. 1.1, bioinformatics approaches in pharmacogenomics are conducted systematically. The lowest level in the system is at the molecular level. At this level, it is necessary to understand the detailed features of a gene and the relationship between genetic structure and function (see Subheading 1.2.1). These detailed features include sequence analytic information such as sequence retrieval and comparison, sequence variation information such as about single-nucleotide polymorphisms (SNPs), and sequence patterns that can correlate sequence structure to functional motifs. 

Tetrahydrofolic acid then functions as a carrier of one-carbon groups for amino acid and nucleotide metabolism. The basic ring system is able to transfer methyl, methylene, methenyl, or formyl groups, and it utilizes slightly different reagents as appropriate. These are shown here for convenience, we have left out the benzoic acid-glutamic acid portion of the structure. These compounds are all interrelated, but we are not going to delve any deeper into the actual biochemical relationships. 

Structural elucidation of natural macromolecules is an important step in understanding the relationships between the chemical properties of a biomolecule and its biological function. The techniques used in organic structure determination (NMR, IR, UV, and MS) are quite useful when applied to biomolecules, but the unique nature of natural molecules also requires the application of specialized chemical techniques. Proteins, polysaccharides, and nucleic acids are polymeric materials, each composed of hundreds or sometimes thousands of monomeric units (amino acids, monosaccharides, and nucleotides, respectively). But there is only a limited number of these types of units from which the biomolecules are synthesized. For example, only 20 different amino acids are found in proteins but these different amino acids may appear several times in the same protein molecule. Therefore, the structure of... 

Amino acids link together linearly to form proteins, nucleotides link linearly to form RNA and DNA, and sugars link in a more complicated way to form complex carbohydrates. The specific sequence in which these units link together to form the final polymeric macromolecule is called its primary structure. In a way that is still very ill-understood, the primary structure ultimately controls the macromolecule s three-dimensional structure and thereby largely determines its function. There is therefore great interest in analyzing primary structural information in order to detect similarities and relationships between macromolecules. However, as we shall see later, although similar primary structures imply similar three-dimensional structures, it is possible for three-dimensional structures to resemble each other without any sequence similarity. 

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