1-Deoxy-D-xylulose-5-phosphate synthase

This thermodynamic driving force is particularly useful tvith multienzyme equilibrium systems such as that used in the gram-scale synthesis of tv ro equivalents ofo-xylulose 5-phosphate (104) from (26) (Figure 10.38) [171,172]. Similarly, the corresponding 1-deoxy-D-xylulose 5-phosphate tvas efficiently produced from pyruvate and (34) by the catalytic action of the thiamine diphosphate-dependent 1-deoxy-D-xylulose 5-phosphate synthase (DXS) (EC 2.2.1.7) from E. coli [173]. 

Lois, L.M. et al.. Carotenoid biosynthesis during tomato fruit development regulatory role of 1-deoxy-D-xylulose 5-phosphate synthase. Plant J. 22, 503, 2000. 

Estevez, J.M. et al., l-Deoxy-D-xylulose-5-phosphate synthase, a limiting enzyme for plastidic isoprenoid biosynthesis in plants, J. Biol. Chem. 276, 22901, 2001. 

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 CPPase substrate DMAPP (15) is formed from isopentenyl pyrophosphate (IPP) (14) via the IPP isomerase reaction. It had been assumed that IPP was generated only via mevalonic acid (12) (Fig. 2), but Rohmer discovered another route, 2-C-methyl-D-erythritol 4-phosphate (13) (MEP) pathway (Fig. 2) [22, 23]. A key step in the MEP pathway is the reaction catalyzed by 1-deoxy-D-xylulose 5-phosphate synthase (DXS), which combines hydroxyethyl thiamine pyrophosphate (hydroxyethyl TPP) generated from pyruvic acid (17) and TPP with glyceral-dehyde 3-phosphate (18) to yield 1-deoxy-D-xylulose 5-phosphate (19) containing five carbons. The mevalonate pathway operates in the cytosol of plants and animals, whereas the MEP pathway is present in the plastid of plants or in eubacteria [24-27]. 

From the many enzymes that are known to make and break C-C bonds, we first chose the two transferases, transketolase (TKT) and transaldolase (TAL), both from the Gram-negative bacterium Escherichia coli. While project B21 evolved, we learned that this microorganism holds other and so far unknown enzymes which are of interest for asymmetric syntheses. One transketolase-like enzyme, 1-deoxy-D-xylulose 5-phosphate synthase (DXS), turned out to be the first enzyme of a novel biosynthetic pathway leading to isoprenoids in bacteria, algae, and plants. The other, fructose 6-phosphate aldolase (ESA) - while similar to transaldolase - allows the direct use of the inexpensive dihydroxyacetone in aldol condensations. 

C-C-Bonding Microbial Enzymes 317 2.2.2.2.2 1-Deoxy-D-xylulose 5-Phosphate Synthase (DXS)... 

Another example of successful engineering of terpene biosynthesis is the constitutive overexpression of the gene encoding the first-step enzyme 1-deoxy-D-xylulose-5-phosphate synthase (DXPS) in the DXP pathway in bacteria and Arabidopsis. In both cases, increased enzyme activity caused increased accumulation of downstream terpenoids, suggesting that DXPS is rate-limiting [8]. 

Acetohydroxy acid synthase (acetolactate synthase) 1-Deoxy-D-xylulose 5-phosphate synthase Transketolase ... 

Colonization of barley, wheat and maize and rice roots by Glomus intraradices resulted in strong induction of transcript levels of the pivotal enzymes of methylerythritol phosphate pathway of isoprenoid biosynthes i.e., 1 -deoxy-D-xylulose 5-phosphate synthase (DXS) and 1 -deoxy-D-xylulose 5-phosphate reductoisomerase (DXR) (Walter et al., 2000). At the same time six cyclohexenone derivatives were characterized from mycorrhizal wheat and maize roots. DXS2 transcript levels are low in most tissues but are strongly stimulated in roots upon colonization by mycorrhizal fungi, correlated with accumulation of carotenoids and apocarotenoids (Walter et al., 2002). Some reports show that the AM symbiosis may cause an increase, decrease, or no change in the plant defense reactions (Guenoune et al., 2001 Mohr et al., 1998). 

Walter M.H., Hans J., StrackD. Two distantly related genes encoding 1-deoxy-D-xylulose 5-phosphate synthases differential regulation in shoots and apocarotenoid-accumulating mycorrhizal roots. Plant J 2002 31 243-254. 

Eubanks LM, Poulter CD. Rhodobacter capsulatus 1-deoxy-D-xylulose 5-phosphate synthase steady-state kinetics and substrate binding. Biochemistry 2003 42 1140-1149. 

Complex xylulose structures can also be synthesized by RAMA1741. Employing a one-pot, three-enzyme system with RAMA, triose phosphate isomerase, and l-deoxy-D-xylulose-5-phosphate synthase, l-deoxy-D-xylulose-5-phosphate could be obtained in 47 % yield[75]. Furthermore, a four-enzyme, one-pot system employing FDP-aldolase from S. camosus furnished 5-deoxy-5-ethyl-D-xylulose1761. 

Schiirmann M, Schiirmann M, Sprenger GA (2002) Fructose 6-phosphate aldolase and 1-deoxy-D-xylulose 5-phosphate synthase from Escherichia coli as tools in enzymatic synthesis of 1-deoxysugars. J Mol Catal B Enzym 19 247-252 Shelton CM, Toone EJ (1995) Differential dye-ligand chromatography as a general purification protocol for 2-keto-3-deoxy-6-phosphogluconate aldolases. Tetrahed Asymm 6 207-211 Silvestri MG, Desantis G, Mitchell M et al. (2003) Asymmetric aldol reactions using aldolases. Top Stereochem 23 267-342... 

In the first path, the PLP precursor pyridoxine 5-phosphate (PNP) is biosynthesized from 3-hydroxy-1-aminoacetone phosphate 1 and DXP 2 (Figure 6.1). DXP 2 is formed from pyruvate 3 and glyceraldehyde 3-phosphate 4, catalyzed by deoxy-D-xylulose 5-phosphate synthase (DXS). The 3-hydroxy-1-aminoacetone phosphate 1 is obtained from the erythrose 4-phosphate 5 in four steps. The first step involves the oxidation of erythrose 4-phosphate 5, mediated by erythrose 4-phosphate dehydrogenase (GapB), to erythronate 4-phosphate 6. The latter is further oxidized by D-erythronate 4-phosphate dehydrogenase (PdxB) to 3-hydroxy-4-phosphohydroxy-a-ketobutyrate 7. Transamination reaction between... 

In spike lavender, an additional copy of the l-deoxy-D-xylulose-5-phosphate synthase gene (DXS), the first enzymatic step in the methylerythritol phosphate (MEP) pathway leading to the precursors of monoterpenes, from Arabidopsis thaliam was introduced and led to an increase of the essential oil of the leaves of up to 360% and of the essential oil of flowers of up to 74% (Munoz-Bertomeu et al., 2006). 

Munoz-Bertomeu, J., I. Arrillaga, R. Ros, and J. Segura, 2006. Up-regulation of l-deoxy-D-xylulose-5-phosphate synthase enhances production of essential oils in transgenic spike lavender. Plant Phys., 142 890-900. 

Kuzuyama T, Takagi M, Takahashi S, Seto H (2000) Cloning and characterization of 1-deoxy-D-xylulose 5-phosphate synthase from Streptomyces sp. Strain CL190, which uses both the mevalonate and nonmevalonate pathways for isopentenyl diphosphate biosynthesis. J Bacteriol 182 891... 

Y. et al. (2013) Feedback inhibition of deoxy-D-xylulose-5-phosphate synthase regulates the methylerythritol 4-phosphate pathway. /. Biol Chem., 288, 16926-16936. 

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