Deoxynucleoside triphosphates

A novel solid phase method for the synthesis of 2 -amino-2 -deoxynucleoside 5 -triphosphates has been developed in which the 3 -azidonucleoside precursors are first linked to support-bound triphenylphosphine as their phosphinimines 116. Following conversion into the triphosphate, the desired 2 -amino-2 -deoxy-nucleoside 5 -triphosphates are released from the support by treatment with ammonia in the Staudinger reaction. ... 

Asymmetric induction (See also Enantioselective) chiral ketones, 62, 106-107 chiral sulfoxides, 8-9 steroid synthesis, 27, 278-281 Asymmetric syntheses. See Enantioselective. .. Asymmetry of vesicle membranes, 351 dATP. See 2 -Deoxynucleoside 5 -triphosphates Atropisomers binap chelands, 102-103 Kemp s acid arylimides, 347 porphyrin oligomers, 348—349 5,10,15,20-tetraarylporphyrins, 253 Axial/equatorial stereoselectivity ... 

DAST — (A -ethylethanaminato)trifluorosulfur (Et2NSF2), 269-270, 272 dATP, See 2 -Deoxynucleoside 5 -triphosphates Davison nickel. See Raney nickel ... 

Mixed deoxynucleotide 5 -triphosphate (dNTP) stock- 10 mM of each 2-deoxynucleoside 5 -triphosphate, deoxyadenosine 5 -tnphosphate (dATP),... 

Fluoro- and 2 -amino-2 -deoxynucleoside 5 -triphosphates are also substrates for T7 RNA Pol. Compared with CTP and UTP, the 2 -modified analogs (2 -F-CTP and 2 -F-UTP) exhibit approximately 500- and 200-fold lower efficiencies respectively, whereas 2 -NH2-UTP is incorporated at a 20-foId... 

During the rephcation of DNA, there must be a separation of the two strands to allow each to serve as a template by hydrogen bonding its nucleotide bases to the incoming deoxynucleoside triphosphate. The separation of the DNA double hehx is promoted by SSBs, specific protein molecules that stabihze the single-stranded structure as the rephcation fork progresses. These stabi-... 

Meyerhans A, Vartanian JP, Hultgren C, Plikat U, Karlsson A, Wang L, Eriksson S, Wain-Hobson S (1994) Restriction and enhancement of human immunodeficiency virus type 1 replication by modulation of intracellular deoxynucleoside triphosphate pools. J Virol 68(l) 535-540... 

Perhaps the most common method of DNA biotinylation is through enzymatic incorporation with the use of a biotin-labeled deoxynucleoside triphosphate. First reported by Langer et al. in... 

Biotin-dUTP derivatives are formed by modification of the C-5 position of uridine. This location is not involved in hydrogen bonding activity with complementary DNA strands, thus hybridization efficiency is not immediately compromised. By contrast, biotin-dCTP or biotin-dATP derivatives involve modification of the bases at the N-4 position of cytosine and the N-6 position of adenine, locations directly involved in hydrogen bond formation with complementary bases. Thus, DNA biotinylation through the use of modified deoxynucleoside triphosphates to be incorporated into existing DNA strands may result in better activity of the probe if dUTP is used over dATP or dCTP. 

All DNA polymerases are single-minded—they can do it only one way. Each dNTP (deoxynucleoside triphosphate) is added to the 3 -OH group of the growing chain so that all chains grow from the 5 end in the dirction 5 to 3. Since strands are antiparallel, the template strand is read in the 3 to 5 direction. This is true of both DNA and RNA synthesis. Most of what you need to know about DNA replication can be summarized in a single picture. 

Terminal deoxynucleotidyl transferase normally adds homopolydeoxynucleotide tails to single-stranded DNA primers in the presence of a deoxynucleoside triphosphate and magnesium. If cobalt is used instead, not only does double-stranded DNA become an acceptable substrate, but ribonucleotides or homopolymer deoxyribo-nucleotide tracts may be added to all forms of duplex DNA at their 3 -ends, regardless of whether these are staggered or even.162 This allows terminal labelling for sequence analysis at the cleavage sites of restriction endonucleases,162- 183 or tail formation for in vitro studies on recombinant DNA.162... 

DNA-directed DNA polymerases [EC 2.7.7.7], also called DNA nucleotidyltransferases (DNA-directed), are enzymes that catalyze the DNA template-directed extension of the 3 -end of a nucleic acid strand one nucleotide at a time. Thus, n deoxynucleoside triphosphates produce n pyrophosphate (or, diphosphate) ions and DNA . This enzyme cannot initiate the synthesis of a polymeric chain de novo it requires a primer which may be DNA or RNA. RNA-directed DNA polymerases [EC 2.7.7.49], also referred to as reverse transcriptases, DNA nucleotidyltransferases (RNA-directed), and revertases, are enzymes that catalyze the RNA template-directed extension of the 3 -end of a nucleic acid strand one nucleotide at a time. Thus, n deoxynucleoside triphosphates produce n pyrophosphate (or, diphosphate) ions and DNA . As was the case above, this enzyme cannot initiate the synthesis of a polymeric chain de novo it requires a primer which may be DNA or RNA. 

This enzyme [EC 2.7.4.6], also known as nucleoside di-phosphokinase and nucleoside 5 -diphosphate phosphotransferase, catalyzes the reaction of ATP with a nucleoside diphosphate to produce ADP and a nucleoside triphosphate. ATP can be substituted by a number of nucleoside triphosphate and deoxynucleoside triphosphate compounds. 

This enzyme [EC 2.7.7.49], also known as RNA-directed DNA polymerase, DNA nucleotidyltransferase (RNA-directed), and revertase, catalyzes the RNA-template-directed extension of the 3 -end of a DNA strand by one deoxynucleotide at a time n deoxynucleoside triphosphate to produce n pyrophosphate (or, diphosphate) and DNA . The enzyme cannot initiate a DNA chain de novo and requires a DNA or RNA primer. See also Viral Polymerases... 

Regulation of ribonucleotide reductase by both positive feedback from ATP and negative feedback by various 2 -deoxynucleoside triphosphates (eg, dATP) is tightly coupled to the need for DNA synthesis. 

Foscamet (Foscavir) is an inorganic pyrophosphate analogue that acts in vitro against HSV-1, HSV-2, VZV, CMV, EB V HBV, and HIV. It acts as a noncompetitive inhibitor of viral DNA polymerase and reverse transcriptase by reversibly binding to the pyrophosphate-binding site of the viral enzyme and preventing the cleavage of pyrophosphate from deoxynucleoside triphosphates. 

There is an alternative method of generating cohesive tails. The enzyme calf thymus terminal (deoxynucleotidyl) transferase adds deoxynucleoside monophosphate residues from 5 -deoxynucleoside triphosphates to protruding 3 -hydroxyl termini in the absence of a template. For example, as shown in equations 14.5 to 14.7,... 

The DNA polymerase is responsible for the accurate copying of a polynucleotide template. It catalyzes nucleophilic attack of the 3 -OH terminus on the a-phosphorus of a deoxynucleoside triphosphate, with displacement of pyrophosphate and incorporation of the nucleoside into the elongating DNA. The reaction involves a template-primer complex and the availability of all... 

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