Cytosine monophosphate

In the simplified notation used here and in the following, the letters C, G, A, U and T do not refer to the nucleobases themselves, but to the nucleotides thus, C corresponds to cytosine monophosphate in the oligonucleotide. 

C-methyl-D-erythritol 2,4-cyclodiphosphate synthase catalyses the conversion of 4-diphospho-cytidyl-2-C-methyl-D-erythritol 2-phosphate to 2-C-methyl-D-erythritol 2,4-cyclodiphosphate (MECDP) (Equation (7)). This reaction is part of the isoprenoid biosynthesis pathway in many plants and bacteria. The structure of the E. coli enzyme bound to Mn, cytosine monophosphate, and 2-C-methyl-D-erythritol 2,4-cyclodiphosphate has been determined. The enzyme in the crystal and probably in solution is trimeric, three monomers are packed in a circular assembly with three-fold symmetry. The active site is at the interface of two adjacent monomers all the ligands bound to the Mn + come from one monomer and a MECDP molecule. The structure of this active site is shown in Figure 29 ... 

Mycophenolate mofetil (MMF) is converted to mycophenolic acid, the active form of the drug. The active product inhibits cytosine monophosphate dehydrogenase and, secondarily, inhibits T-cell lymphocyte proliferation downstream, it interferes with leukocyte adhesion to endothelial cells through inhibition of E-selectin, P-selectin, and intercellular adhesion molecule 1. MMF s pharmacokinetics and toxicities are discussed in Chapter 55. 

Acetyl-CoA ADP Ala AMP ATP BHK CC9C10 CHO CHSE CMP-NANA CoQ CoQH2 DNA acetyl-coenzyme A adenosine diphosphate alanine adenosine monophosphate adenosine triphosphate baby hamster kidney cell line hybridoma cell line Chinese hamster ovary cell line Chinook salmon embryo cell line cytosine monophosphate-N-acetylneuraminic acid coenzyme Q dihydroubiquinone deoxyribonucleic acid... 

In the cytosol, these monosaccharides can be phosphorylated and subsequently coupled with nucleotides such as uridine diphosphate (e.g., UDP-GlcNAc), guanosine diphosphate (e.g., GDP-mannose), or cytosine monophosphate in the case of sialic acids (Fig. 2b) to create a set of high energy building blocks for glycan assembly. In some cases, such as for the initial steps... 

GMP 5 - guanosine monophosphate, 5 - CMP 5 - cytosine monophosphate. HPLC high - pressure liquid chromatography NMR nuclear magnetic resonance, s = singlet, d doublet, t triplet, q = quartet, m multiplet, NOE nuclear Overhauser effect, CD circular dichroism. tn trimethylene diamine, dien diethylene-triamine. CPK models Corey - Pauling - Koltun atomic models. 

FIGURE 50-3 Intracellular activation of nucleoside analog reverse transcriptase inhibitors. Drugs and phosphory-lated anabolites are abbreviated the enzymes responsible for each conversion are spelled out. The active antiretroviral anabolite for each drug is shown in the blue box. Key ZDV, zidovudine d4T, stavudine ddC, dideoxycytidine FTC, emtricitabine 3TC, lamivudine ABC, abacavir ddl, didanosine DF, disoproxil fumarate MP, monophosphate DP, diphosphate TP, triphosphate AMP, adenosine monophosphate CMP, cytosine monophosphate dCMP, deoxycytosine monophosphate IMP, inosine 5 -monophosphate PRPP, phosphoribosyl pyrophosphate NDR, nucleoside diphosphate. 

Figure 20 Apparent formation of 5-hydroxymethylcytosylglucuronic acid from cytosine monophosphate in the biosynthesis of mildiotnycin by S. rimofaciens.

Leloir-GTs utilize sugar nucleotides as activated donor substrates. Sugar moieties bound to nucleoside mono- or diphosphates, like cytosine monophosphate (CMP), thymidine diphosphate (dTDP), guanosine diphosphate (GDP), and the most common uridine diphosphate (UDP), are transferred by two types of Leloir-GTs. 

When RNA is subjected to controlled alkaline hydrolysis eight nucleotides, two isomers each of AMP, GMP, cytosine monophosphate (CMP), and uridine monophosphate (UMP), are formed. These can be separated from one another on columns of anion exchange resins ISl), by paper chromatographic methods 1S2), and by fractional crystallization (iSS). The isomers are the 2 -phosphates ( a ) (XI) and 3 -phosphates ( b ) (XII) which arise from an intermediate cyclic 2, 3 -phosphate mononucleotide ester [Eq. (44)] (1S4-1S6). 

Schyman, P., Laaksonen, A., 8c Hugosson, H. W. (2008). Phosphodiester bond rupture in 5 and 3 cytosine monophosphate in aqueous environment and the effect of low-energy electron attachment A Car-Parrinello QM/MM molecular dynamics study. Chemical Physics Letters, 462, 289. 

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