Cytidine 2-deoxy-5 -methyl-, 3,5-diphosphate

Figure 12 Evidence for an enhanced stability of the Cd as well as the Ca ", Mg, and Co " 1 1 complexes (eq. 2) of ADP ( ), IDP ((g)), and GDP " (O), based on the relationship between log M(R-DP) P H(R-DP) simple M(R-DP) complexes (O), where R-DP = phenyl diphosphate (PhDP ), methyl diphosphate (MeDP ), uridine 5 -diphosphate (UDP ), cytidine 5 -diphosphate (CDP ), thymidine [= l-(2-deoxy-P-D-ribofuranosyl)thymine] 5 -diphosphate (dTDP ), and z-butyl diphosphate (BuDP ) (from left to right). The least-squares lines (eq. 15) are drawn through the indicated six data sets taken from ref. [115]. The points due to the M /NDP systems are based on the values listed in Table 10. The vertical broken lines emphasize the stability differences from the reference lines they equal log m/ndp as defined in analogy to equation (14) (see also Table 10, column 4). All the plotted equilibrium constants refer to aqueous solutions at 25°C and / = 0.1 M (NaNOg).

Figure 9.4 Monoterpene biosynthesis in peppermint oil gland secretory cells. The enzymes involved in this pathway are (1) 1-deoxy-D-xylulose 5-phosphate synthase, (2) 2-C-methyl-D-erythritol 4-phosphate reductoisomerase, (3) 2-C-methyl-D-erythritol 4-phosphate cytidyltransferase, (4) 4-(cytidine 5 -diphospho)-2-C-methyl-D-erythritol kinase, (5) 2-C-methyl-D-erythritol 2,4-cyclodiphosphate synthase, (6) isopentenyl diphosphate isomerase, (7) geranyl diphosphate synthase, (8)...

The de novo pathway to 2 -deoxythymidine monophosphate (dTMP) synthesis first requires the use of dUMP (2 -deoxyuridine-5 -monophosphate) from the metabolism of either UDP or CDP (cytidine diphosphate). The hydrolysis of dUTP (2 -deoxyuridine-5 -triphosphate) to dUMP and subsequent methylation at C-5 by the action of thymidylate synthase, using A, A i°-methylenetetrahydrofolate (THF) as the methyl donor, generate dTMP (Figure 6.54). The latter is subsequently phosphorylated to deoxy-thymidine triphosphate (dTTP) used in DNA synthesis and repair. 

The flavoenzyme from Yersinia pseudotuberculosis (YerD) catalyzes in vivo the acyloin condensation of pyruvate to the ketone, cytidine-5 -diphosphate-3,6-di(deoxy)-4-keto-D-glucose [52]. Investigations on its synthetic capabilities revealed that this enzyme can catalyze aldehyde-ketone cross-acyloin condensations, furnishing tertiary alcohols (Table 10.6) [52], Small cyclic aliphatic ketone derivatives, for example, cydohexanone and methylated cyclohexanones, tetrahydro-2H-pyran-3-one (Table 10.6), open-chain ketones containing an ether moiety, diketones, and ketones containing an - or p-ketoesters were aU successfully converted [52],... 

---