scholarly journals Enterococcus faecalis Acetoacetyl-Coenzyme A Thiolase/3-Hydroxy-3-Methylglutaryl-Coenzyme A Reductase, a Dual-Function Protein of Isopentenyl Diphosphate Biosynthesis

2002 ◽  
Vol 184 (8) ◽  
pp. 2116-2122 ◽  
Author(s):  
Matija Hedl ◽  
Autumn Sutherlin ◽  
E. Imogen Wilding ◽  
Marie Mazzulla ◽  
Damien McDevitt ◽  
...  
Keyword(s):  
Gene Product ◽  
Enterococcus Faecalis ◽  
Active Site ◽  
Coenzyme A ◽  
Mevalonate Pathway ◽  
Dual Function ◽  
Isopentenyl Diphosphate ◽  
Hmg Coa Reductase ◽  
Coa Reductase ◽  
Active Site Histidine

ABSTRACT Many bacteria employ the nonmevalonate pathway for synthesis of isopentenyl diphosphate, the monomer unit for isoprenoid biosynthesis. However, gram-positive cocci exclusively use the mevalonate pathway, which is essential for their growth (E. I. Wilding et al., J. Bacteriol. 182:4319-4327, 2000). Enzymes of the mevalonate pathway are thus potential targets for drug intervention. Uniquely, the enterococci possess a single open reading frame, mvaE, that appears to encode two enzymes of the mevalonate pathway, acetoacetyl-coenzyme A thiolase and 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase. Western blotting revealed that the mvaE gene product is a single polypeptide in Enterococcus faecalis, Enterococcus faecium, and Enterococcus hirae. The mvaE gene was cloned from E. faecalis and was expressed with an N-terminal His tag in Escherichia coli. The gene product was then purified by nickel affinity chromatography. As predicted, the 86.5-kDa mvaE gene product catalyzed both the acetoacetyl-CoA thiolase and HMG-CoA reductase reactions. Temperature optima, ΔHa and Km values, and pH optima were determined for both activities. Kinetic studies of acetoacetyl-CoA thiolase implicated a ping-pong mechanism. CoA acted as an inhibitor competitive with acetyl-CoA. A millimolar Ki for a statin drug confirmed that E. faecalis HMG-CoA reductase is a class II enzyme. The oxidoreductant was NADP(H). A role for an active-site histidine during the first redox step of the HMG-CoA, reductase reaction was suggested by the ability of diethylpyrocarbonate to block formation of mevalonate from HMG-CoA, but not from mevaldehyde. Sequence comparisons with other HMG-CoA reductases suggest that the essential active-site histidine is His756. The mvaE gene product represents the first example of an HMG-CoA reductase fused to another enzyme.

scholarly journals Identification, Evolution, and Essentiality of the Mevalonate Pathway for Isopentenyl Diphosphate Biosynthesis in Gram-Positive Cocci

2000 ◽  
Vol 182 (15) ◽  
pp. 4319-4327 ◽  
Author(s):  
E. Imogen Wilding ◽  
James R. Brown ◽  
Alexander P. Bryant ◽  
Alison F. Chalker ◽  
David J. Holmes ◽  
...  
Keyword(s):  
Mevalonate Pathway ◽  
Genomic Analysis ◽  
Eukaryotic Cell ◽  
Infection Model ◽  
Isopentenyl Diphosphate ◽  
Gram Positive ◽  
Hmg Coa Reductase ◽  
Coa Reductase ◽  
Gram Positive Cocci

ABSTRACT The mevalonate pathway and the glyceraldehyde 3-phosphate (GAP)–pyruvate pathway are alternative routes for the biosynthesis of the central isoprenoid precursor, isopentenyl diphosphate. Genomic analysis revealed that the staphylococci, streptococci, and enterococci possess genes predicted to encode all of the enzymes of the mevalonate pathway and not the GAP-pyruvate pathway, unlike Bacillus subtilis and most gram-negative bacteria studied, which possess only components of the latter pathway. Phylogenetic and comparative genome analyses suggest that the genes for mevalonate biosynthesis in gram-positive cocci, which are highly divergent from those of mammals, were horizontally transferred from a primitive eukaryotic cell. Enterococci uniquely encode a bifunctional protein predicted to possess both 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase and acetyl-CoA acetyltransferase activities. Genetic disruption experiments have shown that five genes encoding proteins involved in this pathway (HMG-CoA synthase, HMG-CoA reductase, mevalonate kinase, phosphomevalonate kinase, and mevalonate diphosphate decarboxylase) are essential for the in vitro growth of Streptococcus pneumoniae under standard conditions. Allelic replacement of the HMG-CoA synthase gene rendered the organism auxotrophic for mevalonate and severely attenuated in a murine respiratory tract infection model. The mevalonate pathway thus represents a potential antibacterial target in the low-G+C gram-positive cocci.

scholarly journals Feedback regulation of 3-hydroxy-3-methylglutaryl coenzyme A reductase in Saccharomyces cerevisiae.

1994 ◽  
Vol 5 (6) ◽  
pp. 655-665 ◽  
Author(s):  
D Dimster-Denk ◽  
M K Thorsness ◽  
J Rine
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Mammalian Cells ◽  
Coenzyme A ◽  
Mevalonate Pathway ◽  
Feedback Regulation ◽  
Eukaryotic Cells ◽  
Yeast Gene ◽  
Hmg Coa Reductase ◽  
Common Precursor ◽  
Coa Reductase

In eukaryotic cells all isoprenoids are synthesized from a common precursor, mevalonate. The formation of mevalonate from 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) is catalyzed by HMG-CoA reductase and is the first committed step in isoprenoid biosynthesis. In mammalian cells, synthesis of HMG-CoA reductase is subject to feedback regulation at multiple molecular levels. We examined the state of feedback regulation of the synthesis of the HMG-CoA reductase isozyme encoded by the yeast gene HMG1 to examine the generality of this regulatory pattern. In yeast, synthesis of Hmg1p was subject to feedback regulation. This regulation of HMG-CoA reductase synthesis was independent of any change in the level of HMG1 mRNA. Furthermore, regulation of Hmg1p synthesis was keyed to the level of a nonsterol product of the mevalonate pathway. Manipulations of endogenous levels of several isoprenoid intermediates, either pharmacologically or genetically, suggested that mevalonate levels may control the synthesis of Hmg1p through effects on translation.

scholarly journals Essentiality, Expression, and Characterization of the Class II 3-Hydroxy-3-Methylglutaryl Coenzyme A Reductase ofStaphylococcus aureus

2000 ◽  
Vol 182 (18) ◽  
pp. 5147-5152 ◽  
Author(s):  
E. Imogen Wilding ◽  
Dong-Yul Kim ◽  
Alexander P. Bryant ◽  
Michael N. Gwynn ◽  
R. Dwayne Lunsford ◽  
...  
Keyword(s):  
Catalytic Mechanism ◽  
Coenzyme A ◽  
Mevalonate Pathway ◽  
Class Ii ◽  
Infection Model ◽  
Gram Positive ◽  
Hmg Coa Reductase ◽  
Coenzyme Specificity ◽  
Apparent Homogeneity ◽  
Coa Reductase

Sequence comparisons have implied the presence of genes encoding enzymes of the mevalonate pathway for isopentenyl diphosphate biosynthesis in the gram-positive pathogen Staphylococcus aureus. In this study we showed through genetic disruption experiments that mvaA, which encodes a putative class II 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, is essential for in vitro growth of S. aureus. Supplementation of media with mevalonate permitted isolation of an auxotrophic mvaAnull mutant that was attenuated for virulence in a murine hematogenous pyelonephritis infection model. The mvaA gene was cloned from S. aureus DNA and expressed with an N-terminal His tag in Escherichia coli. The encoded protein was affinity purified to apparent homogeneity and was shown to be a class II HMG-CoA reductase, the first class II eubacterial biosynthetic enzyme isolated. Unlike most other HMG-CoA reductases, the S. aureus enzyme exhibits dual coenzyme specificity for NADP(H) and NAD(H), but NADP(H) was the preferred coenzyme. Kinetic parameters were determined for all substrates for all four catalyzed reactions using either NADP(H) or NAD(H). In all instances optimal activity using NAD(H) occurred at a pH one to two units more acidic than that using NADP(H). pH profiles suggested that His378 and Lys263, the apparent cognates of the active-site histidine and lysine of Pseudomonas mevaloniiHMG-CoA reductase, function in catalysis and that the general catalytic mechanism is valid for the S. aureus enzyme. Fluvastatin inhibited competitively with HMG-CoA, with a Ki of 320 μM, over 104 higher than that for a class I HMG-CoA reductase. Bacterial class II HMG-CoA reductases thus are potential targets for antibacterial agents directed against multidrug-resistant gram-positive cocci.

scholarly journals Enterococcus faecalis 3-Hydroxy-3-Methylglutaryl Coenzyme A Synthase, an Enzyme of Isopentenyl Diphosphate Biosynthesis

2002 ◽  
Vol 184 (15) ◽  
pp. 4065-4070 ◽  
Author(s):  
Autumn Sutherlin ◽  
Matija Hedl ◽  
Barbara Sanchez-Neri ◽  
John W. Burgner ◽  
Cynthia V. Stauffacher ◽  
...  
Keyword(s):  
Enterococcus Faecalis ◽  
Coenzyme A ◽  
Analytical Ultracentrifugation ◽  
Mevalonate Pathway ◽  
Specific Activity ◽  
Multidrug Resistant ◽  
Isopentenyl Diphosphate ◽  
Acetyl Coa ◽  
Sequence Comparisons ◽  
Apparent Homogeneity

ABSTRACT Biosynthesis of the isoprenoid precursor isopentenyl diphosphate (IPP) proceeds via two distinct pathways. Sequence comparisons and microbiological data suggest that multidrug-resistant strains of gram-positive cocci employ exclusively the mevalonate pathway for IPP biosynthesis. Bacterial mevalonate pathway enzymes therefore offer potential targets for development of active site-directed inhibitors for use as antibiotics. We used the PCR and Enterococcus faecalis genomic DNA to isolate the mvaS gene that encodes 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) synthase, the second enzyme of the mevalonate pathway. mvaS was expressed in Escherichia coli from a pET28 vector with an attached N-terminal histidine tag. The expressed enzyme was purified by affinity chromatography on Ni2+-agarose to apparent homogeneity and a specific activity of 10 μmol/min/mg. Analytical ultracentrifugation showed that the enzyme is a dimer (mass, 83.9 kDa; s 20,w , 5.3). Optimal activity occurred in 2.0 mM MgCl2 at 37oC. The ΔHa was 6,000 cal. The pH activity profile, optimum activity at pH 9.8, yielded a pKa of 8.8 for a dissociating group, presumably Glu78. The stoichiometry per monomer of acetyl-CoA binding was 1.2 ± 0.2 and that of covalent acetylation was 0.60 ± 0.02. The Km for the hydrolysis of acetyl-CoA was 10 μM. Coupled conversion of acetyl-CoA to mevalonate was demonstrated by using HMG-CoA synthase and acetoacetyl-CoA thiolase/HMG-CoA reductase from E. faecalis.

scholarly journals Dietary modification of the activation state of intestinal 3-hydroxy-3-methylglutaryl coenzyme a (HMG-CoA) reductase.

1984 ◽  
Vol 48 (11) ◽  
pp. 2745-2751
Author(s):  
Hirosuke OKU ◽  
Akira MORITA ◽  
Takashi IDE ◽  
Michihiro SUGANO
Keyword(s):  
Coenzyme A ◽  
Dietary Modification ◽  
Hmg Coa Reductase ◽  
Coa Reductase

Inhibition of protein geranylgeranylation induces apoptosis in myeloma plasma cells by reducing Mcl-1 protein levels

Blood ◽  
2003 ◽  
Vol 102 (9) ◽  
pp. 3354-3362 ◽  
Author(s):  
Niels W. C. J. van de Donk ◽  
Marloes M. J. Kamphuis ◽  
Berris van Kessel ◽  
Henk M. Lokhorst ◽  
Andries C. Bloem
Keyword(s):  
Multiple Myeloma ◽  
Plasma Cells ◽  
Mevalonate Pathway ◽  
Cytochrome C Release ◽  
Hmg Coa Reductase ◽  
Myeloma Cells ◽  
Protein Levels ◽  
Geranylgeranyl Transferase ◽  
Induced Apoptosis ◽  
Coa Reductase

AbstractHMG-CoA reductase is the rate-limiting enzyme of the mevalonate pathway leading to the formation of cholesterol and isoprenoids such as farnesylpyrophosphate (FPP) and geranylgeranylpyrophosphate (GGPP). The inhibition of HMG-CoA reductase by lovastatin induced apoptosis in plasma cell lines and tumor cells from patients with multiple myeloma. Here we show that cotreatment with mevalonate or geranylgeranyl moieties, but not farnesyl groups, rescued myeloma cells from lovastatin-induced apoptosis. In addition, the inhibition of geranylgeranylation by specific inhibition of geranylgeranyl transferase I (GGTase I) induced the apoptosis of myeloma cells. Apoptosis triggered by the inhibition of geranylgeranylation was associated with reduction of Mcl-1 protein expression, collapse of the mitochondrial transmembrane potential, expression of the mitochondrial membrane protein 7A6, cytochrome c release from mitochondria into the cytosol, and stimulation of caspase-3 activity. These results imply that protein geranylgeranylation is critical for regulating myeloma tumor cell survival, possibly through regulating Mcl-1 expression. Our results show that pharmacologic agents such as lovastatin or GGTase inhibitors may be useful in the treatment of multiple myeloma.

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