Adenosine nucleotide

The action of rifampicin is upon the /3 subunit of RNA polymerase. Binding of just one molecule of rifampicin inhibits the initiation stage of transeription in whieh the first nucleotide is incorporated in the RNA ehain. Once started, transeription itself is not inhibited. It has been suggested that the stmeture of rifampiein resembles that of two adenosine nucleotides in RNA this may form the basis of the binding of the antibiotic to the j3 subunit. One problem is the rapid development of resistanee in organisms due... 

Miyamoto, K. and French, S.W. (1988). Hepatic adenosine nucleotide metabolism measured in vim in rats fed ethanol and a high fat-low protein diet. Hepatology 8, 53-60. 

Ni2+ is affected profoundly by the phosphates in the nucleotides. The presence of phosphate groups greatly strengthens Ni2+ binding to adenosine nucleotides. 

The removal of introns from pre-messenger RNAs in eukaryotes is catalyzed by the spliceosome, which is a large ribonucleoprotein consisting of at least 70 proteins and five small nuclear RNAs (snRNA) [144]. This splicing pathway involves two phosphotransfer reactions. In the first step, the 5 splice site is attacked by a 2 hydroxy group of an adenosine nucleotide within the intron [indicated by A in Fig. 12] that corresponds to the branch point in the lariat intermediate (Fig. 12,middle). In the second step, the 3 -OH group of the free 5 exon attacks the phosphodiester bond between the intron and... 

C) Lamivudine is a cytosine nucleoside analogue efavirenz is an adenosine nucleotide analogue. 

Kaneider, N.C., Mosheimer, B., Reinisch, N., Patsch, J.R., and Wiedermann, C.J., Inhibition of thrombin-induced signaling by resveratrol and quercetin effects on adenosine nucleotide metabolism in endothelial cells and platelet-neutrophil interactions, Thromb. Res., 114, 185, 2004. 

Critical sequence features of an RNA aptamer that binds ATP are shown in Figure 2 molecules with this general structure bind ATP (and other adenosine nucleotides) with Kd < 50 /xm. Figure 3 presents the three-dimensional structure of a 36 nucleotide RNA aptamer (shown as a complex with AMP) generated by SELEX. This RNA has the backbone structure shown in Figure 2. 

Amino acid attachment site Each tRNA molecule has an attachment site for a specific amino acid at its 3 -end (Figure 31.6). The carboxyl group of the amino acid is in an ester linkage with the 3-hydroxyl of the ribose moiety of the adenosine nucleotide at the 3 -end of the tRNA. [Note When a tRNA has a covalently attached amino acid, it is said to be charged when tRNA is not bound to an amino acid, it is described as being uncharged.] The amino acid that is attached to the tRNA molecule is said to be activated. 

The amino acids in the cytoplasm will not form polypeptides unless activated by ester formation with appropriate tRNA molecules. The ester linkages are through the 3 -OH of the terminal adenosine nucleotide (Equation 25-9) and are formed only under the influence of a synthetase enzyme that is specific for the particular amino acid. The energy for ester formation comes from ATP hydrolysis (Sections 15-5F and 20-10). The product is called an amino-acyl-tRNA. 

The rates of these two complementary reactions can control the amount of either AMP or GMP present in the cell. Each of these reactions is feedback-inhibited by its nucleotide product. Thus, if more adenosine nucleotides exist than guanosine nucleotides, the synthesis of AMP slows down until the purine nucleotides balance. 

Barrett, J. Beis, I. (1973). Nicotinamide and adenosine nucleotide levels in Ascaris lumbricoides, Hymenolepis diminuta and Fasciola hepadca. International Journal for Parasitology, 3 271-3. 

Phosphorylation of ADP to ATP by mitochondria is driven by an electrochemical proton gradient established across the inner mitochondrial membrane as a consequence of vectoral transport of protons from NADH and succinate during oxidation by the respiratory chain (see Chapter 17). Hence, lipophilic weak acids or bases (such as 2,4-dinitrophenol) that can shuttle protons across membranes will dissipate the proton gradient and uncouple oxidation from ADP phosphorylation. Intrami-tochondrial ADP can be rate-limiting as demonstrated by inhibition of the mitochondrial adenosine nucleotide carrier by atractyloside. Inhibition of ATP synthesis... 

Although not as extensively studied as the Fe-protein, adenosine nucleotides, particularly MgADP, can also bind to the MoFe-protein... 

Recent EPR and ENDOR studies on the binding of manganese substituted adenosine nucleotides have been interpreted to suggest that these nucleotides may bind near the P-cluster pair (69). 

Reaction of Adenosine Nucleotides with Methyl 4-Chlorobut-2-ynoate General Procedure ... 

Figure 7.25. RNA Molecule Binds ATP. (A) The Watson-Crick base-pairing pattern, (B) the folding pattern, and (C) a surface representation of an RNA molecule selected to bind adenosine nucleotides. The bound ATP is shown in part B, and the binding site is revealed as a deep pocket in part C.

All living organisms get their chemical energy from ATP and a hydride a reduced form of nicotinamide adenosine nucleotide diphosphate, NADH + H+, or its phosphorylated analog, NADPH + H+(Fig. 1.5). 

Three novel bisubstrate analogues (133a-c) acting as potent inhibitors of 6-hydroxymethyl-7,8-dihydropterin pyrophosphokinase have been synthesised and used in the co-crystallisation of the kinase. These compounds were synthesised by coupling adenosine nucleotides (AMP, ADP and ATP) to 6-hy-... 

M39. Moss, A. H., Solomon, C. C., and Alfrey, A. C., Elevated plasma adenosine nucleotide levels in chronic renal failure and their possible significance. Proc.—Clin. Dial. Transplant. Forum 9, 184-188 (1979). 

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