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PubMed2005

A biosynthetic pathway to isovaleryl-CoA in myxobacteria: the involvement of the mevalonate pathway.

A biosynthetic shunt pathway branching from the mevalonate pathway and providing starter units for branched-chain fatty acid and secondary metabolite biosynthesis has been identified in strains of the myxobacterium Stigmatella aurantiaca. This pathway is upregulated when the branched-chain alpha-keto acid dehydrogenase gene (bkd) is inactivated, thus impairing the normal branched-chain amino acid degradation process. We previously proposed that, in this pathway, isovaleryl-CoA is derived from 3,3-dimethylacrylyl-CoA (DMA-CoA). Here we show that DMA-CoA is an isomerization product of 3-methylbut-3-enoyl-CoA (3MB-CoA). This compound is directly derived from 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) by a decarboxylation/ dehydration reaction resembling the conversion of mevalonate 5-diphosphate to isopentenyl diphosphate. Incubation of cell-free extracts of a bkd mutant with HMG-CoA gave product(s) with the molecular mass of 3MB-CoA or DMA-CoA. The shunt pathway most likely also operates reversibly and provides an alternative source for the monomers of isoprenoid biosynthesis in myxobacteria that utilize L-leucine as precursor.

Acyl Coenzyme A↗
PubMed2004

Analysis of acyl CoA ester intermediates of the mevalonate pathway in Saccharomyces cerevisiae.

The mevalonate pathway plays an important role in providing the cell with a number of essential precursors for the synthesis of biomass constituents. With respect to their chemical structure, the metabolites of this pathway can be divided into two groups: acyl esters [acetoacetyl CoA, acetyl CoA, hydroxymethylglutaryl (HMG) CoA] and phosphorylated metabolites (isopentenyl pyrophosphate, dimethylallyl pyrophosphate, geranyl pyrophosphate, farnesyl pyrophosphate). In this study, we developed a method for the precise analysis of the intracellular concentration of acetoacetyl CoA, acetyl CoA and HMG CoA; and we used this method for quantification of these metabolites in Saccharomyces cerevisiae, both during batch growth on glucose and on galactose and in glucose-limited chemostat cultures operated at three different dilution rates. The level of the metabolites changed depending on the growth phase/specific growth rate and the carbon source, in a way which indicated that the synthesis of acetoacetyl CoA and HMG CoA is subject to glucose repression. In the glucose batch, acetyl CoA accumulated during the growth on glucose and, just after glucose depletion, HMG CoA and acetoacetyl CoA started to accumulate during the growth on ethanol. In the galactose batch, HMG CoA accumulated during the growth on galactose and a high level was maintained into the ethanol growth phase; and the levels of acetyl CoA and HMG CoA were more than two-fold higher in the galactose batch than in the glucose batch.

Acetyl Coenzyme A↗
PubMed2002

Growth-phase dependent expression of the mevalonate pathway in a terpenoid antibiotic-producing Streptomyces strain.

Streptomyces griseolosporeus MF730-N6, a terpenoid antibiotic-terpentecin (Tp) producer, has both the nonmevalonate and mevalonate pathways for the formation of IPP. The Tp biosynthetic gene (ter) and the mevalonate pathway gene cluster (mev) including an HMG-CoA reductase gene (hmgr) had previously been cloned from strain MF730-N6. In this study, two distinct dxs genes (dxs 1 and dxs 2) and a dxr gene, which encode DXP synthases and DXP reductoisomerase, and participate in the initial and the second step of the nonmevalonate pathway, respectively, were cloned. These gene products were expressed in E. coli and confirmed to have the expected activities. The dxs 1, dxs 2, dxr, mev, and ter genes were used for Northern blot and primer extension analyses to examine temporal expression of these genes together with a gap gene coding for GAP dehydrogenase, which was also cloned in this study and used as an internal control. Transcripts of the dxs 1, dxs 2, dxr, and gap genes were detected throughout the cultivation. On the other hand, messages of the mev and ter genes were not detected at early growth phase but appeared when Tp production started. These results suggested that the nonmevalonate pathway and the mevalonate pathway were mainly used for the primary metabolism and the secondary metabolism, respectively, and that both of the two dxs genes were actually transcribed in this strain.

Amino Acid Sequence↗
PubMed2002

[The role of the mevalonate pathway in osteogenic cells].

It has been shown that cholesterol-lowering agents, statins, trigger bone growth in tissue culture and in rodents though inhibiting an enzyme called HMG-CoA reductase which is a key enzyme in a mevalonate pathway. On the other hand, a nitrogen-containing Bisphosphonates, synthetic compounds for the treatment of osteoporosis, induce apoptosis of osteoclasts by inhibiting the enzymes in the mevalonate pathway. These evidences suggest that the mevalonate pathway be closely related not only to cholesterol synthesis but also to bone metabolism. In this paper, the involvement of the mevalonate pathway in bone metabolism is described.

English Abstract↗
PubMed2002

Alendronate inhibits invasion of PC-3 prostate cancer cells by affecting the mevalonate pathway.

Breast and prostate cancer preferentially metastasize in the skeleton, inducing locally increased bone resorption by osteoclasts. Bisphosphonates (BPs), potent inhibitors of osteoclasts and bone resorption, are able to reduce metastatic bone lesions, but the metastasis-related cellular target molecules for BPs have not yet been identified. In osteoclasts, nitrogen-containing BPs inhibit the function of the mevalonate pathway, impairing the prenylation and activation of small GTPases. In addition, direct effects of BPs on cancer cells have been suggested. In the present study, the effects of two clinically used BPs, the amino-BP alendronate and clodronate, on adhesion, invasion, and migration of human PC-3 prostate cancer cells were examined in vitro. We also studied the possible role of the mevalonate pathway in invasion and migration of PC-3 cells using the beta-hydroxy-beta-methylglutaryl-CoA reductase inhibitor mevastatin and the mevalonate pathway intermediates mevalonate (mevalonic acid lactone), geranylgeraniol, and trans-trans-farnesol. The results demonstrate that alendronate pretreatment very effectively inhibited in vitro invasion of prostate cancer cells in a dose-dependent manner, with an IC50 as low as approximately 1 pM. The inhibition was similar to that of mevastatin. Clodronate also inhibited invasion, but the IC50 was 0.1 microM. Importantly, geranylgeraniol and trans-trans-farnesol reversed the inhibitory effect of alendronate and mevastatin but not the clodronate-induced inhibition of invasion. Alendronate pretreatment also inhibited migration, which was partially reversed by geranylgeraniol and trans-trans-farnesol. Adhesion of PC-3 cells to various matrices was reduced, and their F-actin organization was changed. Alendronate pretreatment also inhibited invasion of human Du-145 prostate and MDA-MB-231 breast cancer cells. As a conclusion, the results demonstrate that the mevalonate pathway leading to protein prenylation is important for cancer cell invasion and migration in vitro. They further suggest that interference with this pathway is involved in inhibition of invasion and migration of prostate cancer cells by the amino-BP alendronate but that the mechanism of clodronate inhibition is different. It is possible that BPs have therapeutic potential in preventing the spread of prostate cancer.

Alendronate↗
PubMed1996

Phase I study of lovastatin, an inhibitor of the mevalonate pathway, in patients with cancer.

Lovastatin, an inhibitor of the enzyme 3-hydroxy-3-methylglutaryl-coenzyme A reductase (the major regulatory enzyme of the mevalonate pathway of cholesterol synthesis), displays antitumor activity in experimental models. We therefore conducted a Phase I trial to characterize the tolerability of lovastatin administered at progressively higher doses to cancer patients. From January 1992 to July 1994, 88 patients with solid tumors (median age, 57 +/- 14 years) were treated p.o. with 7-day courses of lovastatin given monthly at doses ranging from 2 to 45 mg/kg/day. The inhibitory effects of lovastatin were monitored through serum concentrations of cholesterol and ubiquinone, two end products of the mevalonate pathway. Concentrations of lovastatin and its active metabolites were also determined, by bioassay, in the serum of selected patients. Cyclical treatment with lovastatin markedly inhibited the mevalonate pathway, evidenced by reductions in both cholesterol and ubiquinone concentrations, by up to 43 and 49% of pretreatment values, respectively. The effect was transient, however, and its magnitude appeared to be dose independent. Drug concentrations reached up to 3.9 micrometer and were in the range associated with antiproliferative activity in vitro. Myopathy was the dose-limiting toxicity. Other toxicities included nausea, diarrhea, and fatigue. Treatment with ubiquinone was associated with reversal of lovastatin-induced myopathy, and its prophylactic administration prevented the development of this toxicity in a cohort of 56 patients. One minor response was documented in a patient with recurrent high-grade glioma. Lovastatin given p.o. at a dose of 25 mg/kg daily for 7 consecutive days is well tolerated. The occurrence of myopathy, the dose-limiting toxicity, can be prevented by ubiquinone supplementation. To improve on the transient inhibitory activity of this dosing regimen on the mevalonate pathway, alternative schedules based on uninterrupted administration of lovastatin should also be studied.

Adult↗
PubMed2000

In vivo effects of bisphosphonates on the osteoclast mevalonate pathway.

Estrogen deficiency is a leading cause of osteoporosis associated with increased osteoclastic bone resorption. In vitro studies indicate that the clinically used nitrogen-containing bisphosphonates (N-BPs) such as alendronate (ALN), risedronate (RIS) and ibandronate (IBA) suppress bone resorption via inhibition of the mevalonate pathway enzyme farnesyl diphosphate (FPP) synthase in osteoclasts (Ocs). The object of this study was to test the hypothesis that N-BPs inhibit the mevalonate pathway of Ocs in vivo. The mevalonate pathway enzyme hydroxymethyl-glutaryl-coenzyme A reductase (HMGR), is modulated by feedback inhibition from downstream metabolites. We therefore evaluated the in vivo expression of HMGR in Ocs from animals treated with BP. The N-BPs, ALN, IBA and RIS, selectively suppressed HMGR expression in up to 85% of rat tibia osteoclasts, after 48 hr treatment. Etidronate and clodronate, bisphosphonates that do not inhibit FPP synthase, were without effect. Simvastatin treatment opposed ALN reduction of HMGR expression, suggesting regulation by a metabolite(s) between mevalonate and FPP. These data provide the first in vivo evidence for N-BP effects on the mevalonate pathway in osteoclasts, and strongly support the hypothesis that N-BPs act via this mechanism.

Alendronate↗
PubMedDate not supplied

Biochemical changes of mevalonate pathway in human colorectal cancer.

BACKGROUND: Alterations in the mevalonate pathway may contribute to malignant cell growth. There are differences in the aetiology, clinical behaviour, pathological and genetic features in cancer of the right versus the left colon. Here, 3-hydroxy-3-methylglutatyl coenzyme A (HMG-CoA) reductase, farnesylpyrophosphate (FPP) synthase and farnesyltransferase (Ftase) activities were measured in human colorectal cancer (CRC) and normal mucosa in order to evaluate their role as potential markers of malignancy, also in relation to cancer location. PATIENTS AND METHODS: HMG-CoA reductase, FPP synthase and Ftase activities were determined in CRC and normal mucosa of 90 patients by radiochemical assay. RESULTS: The enzymatic activities were higher in cancer than in normal mucosa. The tumours located at the left side showed higher HMG-CoA reductase activity, whereas the right side tumours showed higher levels of Ftase and FPP synthase activity. CONCLUSION: The determination of mevalonate pathway enzymes in relation to CRC location may be clinically relevant in designing anticancer targeted therapies.

Aged↗
PubMed2004

Multienzyme mevalonate pathway bioreactor.

The five-carbon metabolic intermediate isopentenyl diphosphate constitutes the basic building block for the biosynthesis of all isoprenoids in all forms of life. Two distinct pathways lead from amphibolic intermediates to isopentenyl diphosphate. The Gram-positive cocci and certain other pathogenic bacteria employ exclusively the mevalonate pathway, a set of six enzyme-catalyzed reactions that convert 3 mol of acetyl-CoA to 1 mol each of carbon dioxide and isopentenyl diphosphate. The survival of the Gram-positive cocci requires a fully functional set of mevalonate pathway enzymes. These enzymes therefore represent potential targets of inhibitors that might be employed as antibiotics directed against multidrug-resistant strains of certain bacterial pathogens. A rapid throughput, bioreactor-based assay to assess the effects of potential inhibitors on several enzymes simultaneously should prove useful for the survey of candidate inhibitors. To approach this goal, and as a proof of concept, we employed enzymes from the Gram-positive pathogen Enterococcus faecalis. Purified recombinant enzymes that catalyze the first three reactions of the mevalonate pathway were immobilized in two kinds of continuous flow enzyme bioreactors: a classical hollow fiber bioreactor and an immobilized plug flow bioreactor that exploited a novel method of enzyme immobilization. Both bioreactor types employed recombinant acetoacetyl-CoA thiolase, HMG-CoA synthase, and HMG-CoA reductase from E. faecalis to convert acetyl-CoA to mevalonate, the central intermediate of the mevalonate pathway. Reactor performance was monitored continuously by spectrophotometric measurement of the concentration of NADPH in the reactor effluent. Additional potential applications of an Ni(++) affinity support bioreactor include using recombinant enzymes from extremophiles for biosynthetic applications. Finally, linking a Ni(++) affinity support bioreactor to an HPLC-mass spectrometer would provide an experimental and pedagogical tool for study of metabolite flux and pool sizes of intermediates to model regulation in intact cells.

Acetyl Coenzyme A↗
PubMed2002

Isoprenylation of RhoB is necessary for its degradation. A novel determinant in the complex regulation of RhoB expression by the mevalonate pathway.

Statins improve vascular functions by mechanisms independent from their cholesterol-lowering effect. Rho GTPases are emerging as key targets for the vascular effects of statins. RhoB is a short-lived, early-response inducible protein involved in receptor endocytosis, apoptosis, and gene expression. Here we show that statins regulate RhoB expression by acting at multiple levels. Simvastatin increased RhoB protein levels by 8- to 10-fold. This effect was related to a depletion of isoprenoid intermediates, as deduced from the observation that several metabolites of the cholesterol biosynthetic pathway, namely, mevalonate and geranylgeranyl-pyrophosphate, attenuated simvastatin-induced RhoB up-regulation. Moreover, prenyltransferase inhibitors mimicked simvastatin effect. Cholesterol supplementation did not prevent simvastatin-elicited up-regulation but increased RhoB levels per se. Simvastatin moderately augmented RhoB transcript levels, but markedly impaired the degradation of RhoB protein, which accumulated in the cytosol in its non-isoprenylated form. Inhibition of RhoB isoprenylation was apparently required for simvastatin-induced up-regulation, because levels of an isoprenylation-deficient RhoB mutant were not affected by simvastatin. Moreover, this mutant was found to be markedly more stable than the wild-type protein. These results show that RhoB isoprenylation is necessary for rapid turnover of this protein and identify a novel link between the cholesterol biosynthetic pathway and the regulation of G-protein expression.

3T3 Cells↗
PubMed2006

Methanocaldococcus jannaschii uses a modified mevalonate pathway for biosynthesis of isopentenyl diphosphate.

Archaea have been shown to produce isoprenoids from mevalonate; however, genome analysis has failed to identify several genes in the mevalonate pathway on the basis of sequence similarity. A predicted archaeal kinase, coded for by the MJ0044 gene, was associated with other mevalonate pathway genes in the archaea and was predicted to be the "missing" phosphomevalonate kinase. The MJ0044-derived protein was tested for phosphomevalonate kinase activity and was found not to catalyze this reaction. The MJ0044 gene product was found to phosphorylate isopentenyl phosphate, generating isopentenyl diphosphate. Unlike other known kinases associated with isoprene biosynthesis, Methanocaldococcus jannaschii isopentenyl phosphate kinase is predicted to be a member of the aspartokinase superfamily.

Archaeal Proteins↗
PubMed1995

Enzymes of the mevalonate pathway in rat liver nodules induced by 2-acetylaminofluorene treatment.

Certain enzymes of the mevalonate pathway have been investigated in persistent liver nodules induced in the rat by 2-acetylaminofluorene. In these nodules the dolichol level was increased 5-fold, the ubiquinone-9 content elevated 6-fold and the amount of cholesterol unchanged. Microsomal beta-hydroxy-beta-methylglutaryl-coenzyme A reductase activity was greatly increased compared to control liver tissue, which was also the case for the cytosolic farnesyl pyrophosphate synthase. A significant elevation of all-transgeranylgeranyl pyrophosphate synthase activity in the cytosol was also observed. The branch-point enzyme of microsomal dolichol synthesis, i.e. cis-prenyltransferase, was decreased in the nodules; whereas the activity of squalene synthase, the terminal regulating enzyme of cholesterol synthesis, remained unchanged. The dolichol species in nodular tissue were redistributed towards the longer chain length species. One factor regulating the chain length of the polyisoprene products formed in vitro was shown to be the ratio of the concentrations of isopentenyl pyrophosphate:farnesyl pyrophosphate employed. Other regulatory factors in the terminal steps of this biosynthetic pathway appear to determine the amounts and nature of the final isoprenoid compounds formed in vivo. In contrast to the microsomal trans-prenyltransferase activity, which was unchanged, the activity of nonaprenyl-4-hydroxybenzoate transferase, an enzyme participating in ubiquinone synthesis, was greatly elevated. The alterations observed in the activities of enzymes in the mevalonate pathway can at least partially explain the increased levels of dolichol and ubiquinone and the unchanged level of cholesterol found in liver nodules. It is reasonable to propose that this modified mevalonate metabolism will render nodular cells resistant to certain toxic factors and prone to cell proliferation.

2-Acetylaminofluorene↗
PubMed2003

Inhibition of mevalonate pathway is involved in alendronate-induced cell growth inhibition, but not in cytokine secretion from macrophages in vitro.

Bisphosphonates are antiresorptive drugs used for the treatment of metabolic bone diseases. They can be divided into two different pharmacological classes: nitrogen-containing and non-nitrogen-containing bisphosphonates. Non-nitrogen-containing bisphosphonates, like clodronate, are metabolised to a toxic ATP-analogue preventing osteoclast mediated bone resorption. Nitrogen-containing bisphosphonates, including alendronate, prevent osteoclast function by inhibiting the mevalonate pathway. Clodronate is known to have anti-inflammatory properties while alendronate induces cytokine secretion from lipopolysaccharide- (LPS) induced macrophages. This study investigates whether the cytotoxicity and cytokine production induced by alendronate and LPS could be counteracted by clodronate or products of mevalonate pathway: oxidized low density lipoprotein (ox-LDL), farnesol and geranylgeraniol. Treatment with alendronate increased LPS-induced secretion of IL-1beta, IL-6 and TNF-alpha from RAW 264 macrophages 2.4-, 1.4- and 1.8-fold, respectively. This treatment was cytotoxic for macrophages as indicated by lowered cell viability. Clodronate and ox-LDL both counteracted the cytokine secretion and cytotoxicity of alendronate. Farnesol and geranylgeraniol did neither reverse the cytokine secretion nor reduce the cytotoxicity of alendronate. Clodronate and ox-LDL were able to counteract the effects of alendronate on macrophages in vitro, probably by their known ability to inhibit DNA binding activity of transcription factors, nuclear factor-kappaB (NF-kappaB) and activating protein-1 (AP-1). These findings suggest that inhibition of mevalonate pathway is not the mechanism responsible for the proinflammatory response caused by alendronate, as it is in alendronate-induced apoptosis and prevention of osteoclast function.

Alendronate↗
PubMed2006

Inhibitors of the mevalonate pathway as potential therapeutic agents in multiple myeloma.

Clinical studies have suggested that bisphosphonates may prolong the survival of sub-sets of myeloma patients. Newer nitrogen containing bisphosphonates such as zoledronate act, at least in part, by inhibiting farnesyl diphosphate synthase and subsequent protein prenylation, furthermore, limited data suggests that zoledronate exerts a direct anti-tumour effect against human myeloma cell lines. We therefore investigated the anti-myeloma potential of zoledronate in comparison to, and in combination with, two other inhibitors of the mevalonate pathway: the HMGCoA reductase inhibitor fluvastatin and the farnesyl transferase inhibitor SCH66336. We found that fluvastatin was able to inhibit the proliferation of myeloma cells more effectively than zoledronate or SCH66336 and that combinations of zoledronate and fluvastatin, but not zoledronate and SCH66336 acted synergistically. Our data indicated that the anti-proliferative effect of mevalonate pathway inhibitors is mediated principally via prevention of geranylgeranylation and is the result of both cell cycle arrest and apoptosis induction. Microarray and quantitative real-time PCR analyses further demonstrated that genes related to apoptosis, cell cycle control, and the mevalonate pathway were particularly affected by zoledronate and fluvastatin, and that some of these genetic effects were synergistic. We conclude that the mechanisms of geranylgeranylation inhibition mediated anti-myeloma effects warrant further evaluation and may provide novel targets for future therapeutic development.

Apoptosis↗
PubMed2001

Cloning of a gene cluster encoding enzymes responsible for the mevalonate pathway from a terpenoid-antibiotic-producing Streptomyces strain.

A gene cluster encoding enzymes responsible for the mevalonate pathway was isolated from Streptomyces griseolosporeus strain MF730-N6, a terpenoid-antibiotic terpentecin producer, by searching a flanking region of the 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase gene, which had been previously isolated by complementation. By DNA sequencing of an 8.9-kb BamHI fragment, 7 genes encoding geranylgeranyl diphosphate synthase (GGDPS), mevalonate kinase (MK), mevalonate diphosphate decarboxylase (MDPD), phosphomevalonate kinase (PMK), isopentenyl diphosphate (IPP) isomerase, HMG-CoA reductase, and HMG-CoA synthase were suggested to exist in that order. Heterologous expression of these genes in E. coli and Streptomyces lividans, both of which have only the nonmevalonate pathways, suggested that the genes for the mevalonate pathway were included in the cloned DNA fragment. The GGDPS, MK, MDPD, PMK, IPP isomerase, and HMG-CoA synthase were expressed in E. coli. Among them, the recombinant GGDPS, MK, and IPP isomerase were confirmed to have the expected activities. This is the first report, to the best of our knowledge, about eubacterial MK with direct evidence.

Alkyl and Aryl Transferases↗
PubMed2001

The non-mevalonate pathway of isoprenoids: genes, enzymes and intermediates.

Although the mevalonate pathway had been considered for a long time as the unique source of biosynthetic isoprenoids, an alternative pathway has recently been discovered. The first intermediate, 1-deoxy-D-xylulose 5-phosphate, is assembled by condensation of glyceraldehyde 3-phosphate and pyruvate. A skeletal rearrangement coupled with a reduction step affords the branched-chain polyol, 2C-methyl-D-erythritol 4-phosphate, which is subsequently converted into a cyclic 2,4-diphosphate by the consecutive action of three enzymes via nucleotide diphosphate intermediates. The genes specifying these enzymes have been cloned from bacteria, plants and protozoa. Their expression in recombinant bacterial hosts has opened the way to the identification of several novel pathway intermediates.

Archaea↗
PubMed2004

Selenoproteins, cholesterol-lowering drugs, and the consequences: revisiting of the mevalonate pathway.

3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) and peroxisome proliferator-activated receptor alpha activators (fibrates) are the backbone of pharmacologic hypercholesterolemia and dyslipidemia treatment. Many of their clinical effects, however, are still enigmatic. This article describes how a side road of the mevalonate pathway, characterized in recent years, can rationalize a major fraction of these unexplained observations. This side road is the enzymatic isopentenylation of selenocysteine-tRNA([Ser]Sec) (Sec-tRNA), the singular tRNA to decode the unusual amino acid selenocysteine. The functionally indispensable isopentenylation of Sec-tRNA requires a unique intermediate from the mevalonate pathway, isopentenyl pyrophosphate, which concomitantly constitutes the central building block for cholesterol biosynthesis, and whose formation is suppressed by statins and fibrates. The resultant inhibition of Sec-tRNA isopentenylation profoundly decreases selenoprotein expression. This effect might seamlessly explain the immunosuppressive, redox, endothelial, sympatholytic, and thyroidal effects of statins and fibrates as well as their common side effects and drug interactions.

Animals↗
PubMed2003

Crystal structure of 4-(cytidine 5'-diphospho)-2-C-methyl-D-erythritol kinase, an enzyme in the non-mevalonate pathway of isoprenoid synthesis.

The crystal structure of the enzyme 4-(cytidine 5'-diphospho)-2-C-methyl-D-erythritol (CDP-ME) kinase from the thermophilic bacterium Thermus thermophilus HB8 has been determined at 1.7-A resolution. This enzyme catalyzes phosphorylation of the 2-hydroxyl group of CDP-ME, the fourth step of the non-mevalonate pathway, which is essential for isoprenoid biosynthesis in several pathogenic microorganisms. Since this pathway is absent in humans, it is an important target for the development of novel antimicrobial compounds. The structure of the enzyme is similar to the structures of mevalonate kinase and homoserine kinase, members of the GHMP superfamily. Lys8 and Asp125 are active site residues in mevalonate kinase that also appear to play a catalytic role in CDP-ME kinase. Both the mevalonate and the non-mevalonate pathways therefore involve closely related kinases with similar mechanisms. Assaying the enzyme showed that CDP-ME kinase will phosphorylate CDP-ME but not 4-(uridine 5'-diphospho)-2-C-methyl-D-erythritol, indicating the substrate pyrimidine moiety is involved in important interactions with the enzyme.

Amino Acid Sequence↗