Background And Aims: Familial hypercholesterolemia (FH) is among the most common genetic disorders in primary care. However, only 15% or less of patients are diagnosed, and few achieve the goals for low-density lipoprotein cholesterol (LDL-C). In this analysis of the German Cascade Screening and Registry for High Cholesterol (CaRe High), we examined the status of lipid management, treatment strategies, and LDL-C goal attainment according to the ESC/EAS dyslipidemia guidelines.
View Article and Find Full Text PDFBackground: The phosphoenolpyruvate (PEP):lactose phosphotransferase system of Staphylococcus aureus transports and phosphorylates lactose and various phenylgalactosides. Their phosphorylation is catalyzed by the Cys476-phosphorylated EIIB domain of the lactose-specific permease enzyme IICB (EIICBLac). Phosphorylation causes the release of galactosides bound to the EIIC domain into the cytoplasm by a mechanism not yet understood.
View Article and Find Full Text PDFEubacteria can import and simultaneously phosphorylate a range of different carbohydrates by means of sugar specific phosphoenolpyruvate (PEP) dependent sugar phosphotransferase systems (PTSs). Here, we report the biochemical characterization of the gluconate specific PTS component EIIA(gnt) from Enterococcus faecalis and its unexpectedly strong complex with EIIB(gnt). We analyze the activity of the complex regarding phosphoryl transfer using kinetic measurements and demonstrate by mutagenesis that His-9 of EIIA(gnt) is essential for this process and represents most likely the phosphoryl group carrier of EIIA(gnt).
View Article and Find Full Text PDFBiochem Biophys Res Commun
October 2009
In Eubacteria, the utilization of a number of extracellular carbohydrates is mediated by sugar specific phosphoenolepyruvate (PEP) dependent sugar phosphotransferase systems (PTSs), which simultaneously import und phosphorylate their target sugars. Here, we report the crystal structure of the EIIA(gnt) component of the so far little investigated Enterococcus faecalis gluconate specific PTS. The crystal structure shows a tightly interacting dimer of EIIA(gnt) which is structurally similar to the related EIIA(man) from Escherichia coli.
View Article and Find Full Text PDFRecently, the genetic variant Y402H in the CFH (complement factor H) gene was associated with an increased risk for MI (myocardial infarction) in a prospective Caucasian cohort. In another nested case-control study, however, the CFH-Y402H variant did not carry susceptibility to MI. The aim of the present study was to test for an association between the CFH-Y402H variant and MI in a large case-control sample with a familial background for CAD (coronary artery disease).
View Article and Find Full Text PDFEnzyme I (EI) is the phosphoenolpyruvate (PEP)-protein phosphotransferase at the entry point of the PEP-dependent sugar phosphotransferase system, which catalyzes carbohydrate uptake into bacterial cells. In the first step of this pathway EI phosphorylates the heat-stable phospho carrier protein at His-15 using PEP as a phosphoryl donor in a reaction that requires EI dimerization and autophosphorylation at His-190. The structure of the full-length protein from Staphylococcus carnosus at 2.
View Article and Find Full Text PDFHigh-pressure NMR experiments performed on the histidine-containing phosphocarrier protein (HPr) from Staphylococcus carnosus have shown that residue Ile14, which is located in the active-centre loop, exhibits a peculiarly small pressure response. In contrast, the rest of the loop shows strong pressure effects as is expected for typical protein interaction sites. To elucidate the structural role of this residue, the mutant protein HPr(I14A), in which Ile14 is replaced by Ala, was produced and studied by solution NMR spectroscopy.
View Article and Find Full Text PDFInfrequent structural fluctuations of a globular protein is seldom detected and studied in detail. One tyrosine ring of HPr from Staphylococcus carnosus, an 88-residue phosphocarrier protein with no disulfide bonds, undergoes a very slow ring flip, the pressure and temperature dependence of which is studied in detail using the on-line cell high-pressure nuclear magnetic resonance technique in the pressure range from 3 MPa to 200 MPa and in the temperature range from 257 K to 313 K. The ring of Tyr6 is buried sandwiched between a beta-sheet and alpha-helices (the water-accessible area is less than 0.
View Article and Find Full Text PDFA high-resolution structure of the histidine-containing phosphocarrier protein (HPr) from Staphylococcus aureus was obtained by heteronuclear multidimensional nuclear magnetic resonance (NMR) spectroscopy on the basis of 1,766 structural restraints. Twenty-three hydrogen bonds in HPr could be directly detected by polarization transfer from the amide nitrogen to the carbonyl carbon involved in the hydrogen bond. Differential line broadening was used to characterize the interaction of HPr with the HPr kinase/phosphorylase (HPrK/P) of Staphylococcus xylosus, which is responsible for phosphorylation-dephosphorylation of the hydroxyl group of the regulatory serine residue at position 46.
View Article and Find Full Text PDFThe interaction between the histidine-containing phosphocarrier protein HPr and xenon atoms in solution is studied in the present paper. Wild-type HPr as well as the exchange mutant I14A have been studied. Specific binding of xenon into an engineered cavity created via the exchange of amino acid residue I14 by alanine could be shown using 1H-15N heteronuclear single-quantum coherence (HSQC) spectroscopy.
View Article and Find Full Text PDFIn most Gram-positive bacteria, serine-46-phosphorylated HPr (P-Ser-HPr) controls the expression of numerous catabolic genes ( approximately 10% of their genome) by acting as catabolite corepressor. HPr kinase/phosphorylase (HprK/P), the bifunctional sensor enzyme for catabolite repression, phosphorylates HPr, a phosphocarrier protein of the sugar-transporting phosphoenolpyruvate/glycose phosphotransferase system, in the presence of ATP and fructose-1,6-bisphosphate but dephosphorylates P-Ser-HPr when phosphate prevails over ATP and fructose-1,6-bisphosphate. We demonstrate here that P-Ser-HPr dephosphorylation leads to the formation of HPr and pyrophosphate.
View Article and Find Full Text PDFSimilarities between protein three-dimensional structures can reveal evolutionary and functional relationships not apparent from sequence comparison alone. Here we report such a similarity between the metabolic enzymes histidine phosphocarrier protein kinase (HPrK) and phosphoenolpyruvate carboxykinase (PCK), suggesting that they are evolutionarily related. Current structure classifications place PCK and other P-loop containing nucleotidyl-transferases into different folds.
View Article and Find Full Text PDFThe histidine containing phospho carrier protein (HPr) kinase/phosphatase is involved in carbon catabolite repression, mainly in Gram-positive bacteria. It is a bifunctional enzyme that phosphorylates Ser-46-HPr in an ATP-dependent reaction and dephosphorylates P-Ser-46-HPr. X-ray analysis of the full-length crystalline enzyme from Staphylococcus xylosus at a resolution of 1.
View Article and Find Full Text PDFAppl Environ Microbiol
February 2002
Purification of xylulose 5-phosphate phosphoketolase (XpkA), the central enzyme of the phosphoketolase pathway (PKP) in lactic acid bacteria, and cloning and sequence analysis of the encoding gene, xpkA, from Lactobacillus pentosus MD363 are described. xpkA encodes a 788-amino-acid protein with a calculated mass of 88,705 Da. Expression of xpkA in Escherichia coli led to an increase in XpkA activity, while an xpkA knockout mutant of L.
View Article and Find Full Text PDFThe hydrophilic part of membrane proteins plays an important role in the formation of 3D crystals. The construction of fusion proteins using well crystallizing proteins as fusion partners is a possibility to increase the hydrophilic part of membrane proteins lacking large hydrophilic domains. These fusion proteins might be easier to crystallize.
View Article and Find Full Text PDFThe histidine-containing phosphocarrier protein (HPr) transfers a phosphate group between components of the prokaryotic phosphoenolpyruvate-dependent phosphotransferase system (PTS), which is finally used to phosphorylate the carbohydrate transported by the PTS through the cell membrane. Recently it has also been found to act as an intermediate in the signaling cascade that regulates transcription of genes related to the carbohydrate-response system. Both functions involve phosphorylation/dephosphorylation reactions, but at different sites.
View Article and Find Full Text PDFThe histidine-containing phosphocarrier protein HPr is a central component of the phosphoenolpyruvate:sugar phosphotransferase system (PTS), which transfers metabolic carbohydrates across the cell membrane in many bacterial species. In Gram-positive bacteria, phosphorylation of HPr at conserved serine 46 (P-Ser-HPr) plays several regulatory roles within the cell; the major regulatory effect of P-Ser-HPr is its inability to act as a phosphocarrier substrate in the enzyme I reaction of the PTS. In order to investigate the structural nature of HPr regulation by phosphorylation at Ser46, the structure of the P-Ser-HPr from the Gram- positive bacterium Enterococcus faecalis has been determined.
View Article and Find Full Text PDFThe ptsG operon of Staphylococcus carnosus consists of two adjacent genes, glcA and glcB, encoding glucose- and glucoside-specific enzymes II, respectively, the sugar permeases of the phosphoenolpyruvate-dependent phosphotransferase system (PTS). The expression of the ptsG operon is glucose-inducible. Putative RAT (ribonucleic antiterminator) and terminator sequences localized in the promoter region of glcA suggest regulation via antitermination.
View Article and Find Full Text PDFSeveral amino acids in the active center of the 6-phospho-beta-galactosidase from Lactococcus lactis were replaced by the corresponding residues in homologous enzymes of glycosidase family 1 with different specificities. Three mutants, W429A, K435V/Y437F and S428D/ K435V/Y437F, were constructed. W429A was found to have an improved specificity for glucosides compared with the wild-type, consistent with the theory that the amino acid at this position is relevant for the distinction between galactosides and glucosides.
View Article and Find Full Text PDFThe pressure-induced changes in 15N enriched HPr from Staphylococcus carnosus were investigated by two-dimensional (2D) heteronuclear NMR spectroscopy at pressures ranging from atmospheric pressure up to 200 MPa. The NMR experiments allowed the simultaneous observation of the backbone and side-chain amide protons and nitrogens. Most of the resonances shift downfield with increasing pressure indicating generalized pressure-induced conformational changes.
View Article and Find Full Text PDFPrevious sequence analysis of the glucose-specific PTS gene locus from Staphylococcus carnosus revealed the unexpected finding of two adjacent, highly similar ORFs, glcA and glcB, each encoding a glucose-specific membrane permease EIICBA(Glc). glcA and glcB show 73% identity at the nucleotide level and glcB is located 131 bp downstream from glcA. Each of the genes is flanked by putative regulatory elements such as a termination stem-loop, promoter and ribosome-binding site, suggesting independent regulation.
View Article and Find Full Text PDFThe HPr kinase of Gram-positive bacteria is an ATP-dependent serine protein kinase, which phosphorylates the HPr protein of the bacterial phosphotransferase system (PTS) and is involved in the regulation of carbohydrate metabolism. The hprK gene from Enterococcus faecalis was cloned via polymerase chain reaction (PCR) and sequenced. The deduced amino acid sequence was confirmed by microscale Edman degradation and mass spectrometry combined with collision-induced dissociation of tryptic peptides derived from the HPr kinase of E.
View Article and Find Full Text PDFThe lactose-specific enzyme II (IICBlac) of the phosphoenolpyruvate-dependent phosphotransferase system (PTS) of Staphylococcus aureus couples translocation to phosphorylation of the transported lactose. It is composed of the N-terminal membrane-bound IIC domain, which includes the sugar-binding site, and the C-terminal IIB domain, which contains the phosphorylation site at Cys476. IIC (residues 1-461) fused with a C-terminal affinity tag of six histidine residues and IIB (residues 461-570) fused with an N-terminal histidine tag were overexpressed in Escherichia coli and purified by Ni2+ chelate affinity chromatography.
View Article and Find Full Text PDFBased on the complete sequential assignment of the 1H-NMR spectrum by multidimensional NMR techniques the secondary structure and the local geometry of the active site of histidine-containing phosphocarrier protein (HPr) from Enterococcus faecalis were elucidated. We present a comparative analysis of the active site in the seven known structures of HPr from different organisms determined by NMR or X-ray crystallography. In catalysis, HPr is phosphorylated at the ring N61 of His15.
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