Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0519030 (Klebsiella)
 21,988 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A ribitol dehydrogenase (ribitol-NAD(+) oxidoreductase, EC. 1.1.1.56) having increased specificity and catalytic efficiency toward xylitol was isolated from mutant strains of Klebsiella aerogenes, which were selected for increased growth rate on xylitol over the ribitol dehydrogenase constitutive wild-type organism. 2. The mutant enzyme was purified to homogeneity and its general characteristics were compared with those of the previously purified wild-type enzyme. 3. Initial-velocity steady-state kinetic parameters were determined for both wild-type and mutant enzymes and the results compared. 4. The results are interpreted in terms of a model in which the mutant enzyme results from a small change of amino acid sequence, which affects both the stability and conformational equilibria of the molecule.
 ...
PMID:A comparison of wild-type and mutant ribitol dehydrogenases from Klebsiella aerogenes. 437 42

In Klebsiella pneumoniae NCIB 418, the pathways normally responsible for aerobic growth on glycerol and sn-glycerol 3-phosphate (the glp system) are superrepressed. However, aerobic growth on glycerol can take place by the intervention of the NAD-linked glycerol dehydrogenase and the ATP-dependent dihydroxyacetone kinase of the dha system normally inducible only anaerobically by glycerol or dihydroxyacetone. Conclusive evidence that the dha system is responsible for both aerobic and anaerobic dissimilation of glycerol was provided by a Tn5 insertion mutant lacking dihydroxyacetone kinase. An enzymatically coupled assay specific for this enzyme was devised. Spontaneous reactivation of the glp system was achieved by selection for aerobic growth on sn-glycerol 3-phosphate or on limiting glycerol as the sole carbon and energy source. However, the expression of this system became constitutive. Aerobic operation of the glp system highly represses synthesis of the dha system enzymes by catabolite repression.
 ...
PMID:DHA system mediating aerobic and anaerobic dissimilation of glycerol in Klebsiella pneumoniae NCIB 418. 628 4

By the enrichment culture technique 14 gram-negative bacteria and two yeast strains were isolated that used D(+)-malic acid as sole carbon source. The bacteria were identified as Pseudomonas putida, Pseudomonas fluorescens, Pseudomonas aeruginosa and Klebsiella aerogenes. In cell-free extracts of P. fluorescens and P. putida the presence of malate dehydrogenase, D-malic enzyme (NAD-dependent) and L-malic enzyme (NADP-dependent) was demonstrated. D-Malic enzyme from P. fluorescens was purified. Stabilization of the enzyme by 50 mM ammonium sulphate an 1 mM EDTA was essential. Preparation of D-malic enzyme that gave one band with disc gel electrophoresis showed a specific activity of 4-5 U/mg. D-Malic enzyme requires divalent cations. The Km values were for malate Km = 0.3 mM and for NAD Km = 0.08 mM. The pH optimum for the reaction was found to be in the range of pH 8.1 to pH 8.8. D-Malic enzyme is partially inhibited by oxaloacetic acid, meso-tartaric acid, D-lactic acid and ATP. Determined by gel filtration and gradient gel electrophoresis, the molecular weight was approximately 175 000.
 ...
PMID:D-Malic enzyme of Pseudomonas fluorescens. 680 38

The first enzyme in the formation of GDP-L-fucose from GDP-D-mannose, which forms a GDP-4-keto sugar intermediate, was purified to homogeneity from cell extracts of Klebsiella pneumoniae. During purification, the enzyme was found to be highly activated by NADP. It was proven that the pyridine nucleotide coenzyme of the enzyme was NADP, not NAD, which differs from previously accepted information. NAD had no effect on enzyme activity. The product of the enzyme reaction with NADP as coenzyme was separated from other nucleotides by high-performance liquid chromatography, and using ion spray liquid chromatography/mass spectrometry the mass was determined for the first time, as 587, which is same as the calculated mass of GDP-4-keto-6-deoxy-D-mannose.
 ...
PMID:Evidence that the enzyme catalyzing the conversion of guanosine diphosphate D-mannose to a 4-keto sugar nucleotide intermediate requires nicotinamide adenine dinucleotide phosphate. 767 67

There is an astonishing array of microbial alcohol oxidoreductases. They display a wide variety of substrate specificities and they fulfill several vital but quite different physiological functions. Some of these enzymes are involved in the production of alcoholic beverages and of industrial solvents, others are important in the production of vinegar, and still others participate in the degradation of naturally occurring and xenobiotic aromatic compounds as well as in the growth of bacteria and yeasts on methanol. They can be divided into three major categories. (1) The NAD- or NADP-dependent dehydrogenases. These can in turn be divided into the group I long-chain (approximately 350 amino acid residues) zinc-dependent enzymes such as alcohol dehydrogenases I, II, and III of Saccharomyces cerevisiae or the plasmid-encoded benzyl alcohol dehydrogenase of Pseudomonas putida; the group II short-chain (approximately 250 residues) zinc-independent enzymes such as ribitol dehydrogenase of Klebsiella aerogenes; the group III "iron-activated" enzymes that generally contain approximately 385 amino acid residues, such as alcohol dehydrogenase II of Zymomonas mobilis and alcohol dehydrogenase IV of Saccharomyces cerevisiae, but may contain almost 900 residues in the case of the multifunctional alcohol dehydrogenases of Escherichia coli and Clostridium acetobutylicum. The aldehyde/alcohol oxidoreductase of Amycolatopsis methanolica and the methanol dehydrogenases of A. methanolica and Mycobacterium gasti are 4-nitroso-N,N-dimethylaniline-dependent nicotinoproteins. (2) NAD(P)-independent enzymes that use pyrroloquinoline quinone, haem or cofactor F420 as cofactor, exemplified by methanol dehydrogenase of Paracoccus denitrificans, ethanol dehydrogenase of Acetobacter and Gluconobacter spp. and the alcohol dehydrogenases of certain archaebacteria. (3) Oxidases that catalyze an essentially irreversible oxidation of alcohols, such as methanol oxidase of Hansenula polymorpha and probably the veratryl alcohol oxidases of certain fungi involved in lignin degradation. This review deals mainly with those enzymes for which complete amino acid sequences are available. The discussion focuses on a comparison of their primary, secondary, tertiary, and quaternary structures and their catalytic mechanisms. The physiological roles of the enzymes and isoenzymes are also considered, as are their probable evolutionary relationships.
 ...
PMID:Molecular characterization of microbial alcohol dehydrogenases. 818 33

An approximately 70-kDa protein in the culture supernatant of a human pathogenic strain of Klebsiella pneumoniae was labeled in the presence of [32P-adenylate]NAD. Labeling was significantly increased by the addition of dithiothreitol ( > 1 mM) but prevented by treatment of the culture supernatant for 3 min at 56 degrees C. The addition of unlabeled NAD, but not of ADP-ribose, blocked labeling of the approximately 70-kDa protein. The radioactive label was released by formic acid but not by HgCl2 (1 mM) or neutral hydroxylamine (0.5 M). The addition of homogenates of human platelets, human neutrophils, rat brain, rat lung, or rat spleen tissues to the culture supernatant did not induce labeling of eukaryotic proteins. The data indicate that the K. pneumoniae strain produces ADP-ribosyltransferase which modifies an endogenous protein.
 ...
PMID:ADP-ribosylation of an approximately 70-kilodalton protein of Klebsiella pneumoniae. 861 83

The acoD gene, which encodes a dihydrolipoamide dehydrogenase component of the acetoin dehydrogenase enzyme system of Klebsiella pneumoniae was isolated and the nucleotide sequence determined. The gene is capable of encoding a protein of 465 amino acid residues with conserved binding domains for NAD and FAD, and two redox-active cysteine residues. The acoD gene product exhibited a Michaelis constant of 170 microM for NAD, while NADP can not be used as a substrate. The purified enzyme appeared to be a dimer of the acoD gene product. It did not associate tightly with the E1 and E2 components of either acetoin dehydrogenase or 2-oxoglutarate dehydrogenase to form an active multi-enzyme complex.
 ...
PMID:Identification and characterization of the acoD gene encoding a dihydrolipoamide dehydrogenase of the Klebsiella pneumoniae acetoin dehydrogenase system. 882 47

The O-side-chain polysaccharide in the lipopolysaccharide of Klebsiella pneumoniae O1 is based on a backbone structure of repeat units of [-->3)-beta-D-Galf-(1-->3)-alpha-D-Galp-(1-->]; this structure is termed D-galactan I. The rfb (O-antigen biosynthesis) gene cluster directs the synthesis of D-galactan I and consists of six genes termed rfbA-FKPO1. In this paper we show that rfbDKPO1 encodes a UDP-galactopyranose mutase (NAD(P)H-requiring) (EC 5.4.99. 9), which forms uridine 5'-(trihydrogen diphosphate) P'-alpha-D-galactofuranosyl ester (UDP-Galf), the biosynthetic precursor of galactofuranosyl residues. The deduced amino acid sequence of rfbDKPO1 shows 85% and 37.5% identity to the rfbDKPO8 gene of K. pneumoniae serotype O8 and the glf gene of Escherichia coli, respectively. The molecular mass of the purified RfbDKPO1 enzyme is 45 kDa as determined by SDS-polyacrylamide gel electrophoresis, while gel filtration revealed a molecular mass of 92 kDa, suggesting a dimeric structure for the native protein. The rfbDKPO1 gene product interconverts uridine 5'-(trihydrogen diphosphate) P'-alpha-D-galactopyranosyl ester (UDP-Galp) and UDP-Galf. Unlike Glf, RfbDKPO1 showed a requirement for NADH or NADPH, which could not be replaced by NAD or NADP. RfbDKPO1 was used to synthesize milligram quantities of UDP-Galf, allowing this compound to be purified and fully characterized in an intact form for the first time. The structure of UDP-Galf was proven by NMR spectroscopy.
 ...
PMID:UDP-galactofuranose precursor required for formation of the lipopolysaccharide O antigen of Klebsiella pneumoniae serotype O1 is synthesized by the product of the rfbDKPO1 gene. 902 Jan 23

The bacteria Klebsiella oxytoca LMD 72.65 (ATCC 8724), Arthrobacter P1 LMD 81.60 (NCIB 11625), Paracoccus versutus LMD 80.62 (ATCC 25364), Escherichia coli W LMD 50.28 (ATCC 9637), E. coli K12 LMD 93.68, Pseudomonas aeruginosa PAO1 LMD 89.1 (ATCC 17933) and Pseudomonas putida LMD 68.20 (ATCC 12633) utilized primary amines as a carbon and energy source, although the range of amines accepted varied from organism to organism. The Gram-negative bacteria K. oxytoca and E. coli as well as the Gram-positive methylotroph Arthrobacter P1 used an oxidase whereas the pseudomonads and the Gram-negative methylotroph Paracoccus versutus used a dehydrogenase for amine oxidation. K. oxytoca utilized several primary amines but showed a preference for those containing a phenyl group moiety. Only a single oxidase was used for oxidation of the amines. After purification, the following characteristics of the enzyme indicated that it belonged to the group of copper-quinoprotein amine oxidase (EC 1.4.3.6): the molecular mass (172,000 Da) of the homodimeric protein; the UV/visible and EPR spectra of isolated and p-nitrophenylhydrazine-inhibited enzyme; the presence and the content of copper and topaquinone (TPQ). The amine oxidase appeared to be soluble and localized in the periplasm, but catalase and NAD-dependent aromatic aldehyde dehydrogenase, enzymes catalysing the conversion of its reaction products, were found in the cytoplasm. From the amino acid sequence of the N-terminal part as well as that of a purified peptide, it appears that K. oxytoca produces a copper-quinoprotein oxidase which is very similar to that found in other Enterobacteriaceae.
 ...
PMID:Distribution of amine oxidases and amine dehydrogenases in bacteria grown on primary amines and characterization of the amine oxidase from Klebsiella oxytoca. 904 25

We have recently proposed the existence of a bacteriocolonic pathway for ethanol oxidation [i.e., ethanol is oxidized by alcohol dehydrogenases (ADHs) of intestinal bacteria resulting in high intracolonic levels of reactive and toxic acetaldehyde]. The aim of this in vitro study was to characterize further ADH activity of some aerobic bacteria, representing the normal human colonic flora. These bacteria were earlier shown to possess high cytosolic ADH activities (Escherichia coli IH 133369, Klebsiella pneumoniae IH 35385, Klebsiella oxytoca IH 35339, Pseudomonas aeruginosa IH 35342, and Hafnia alvei IH 53227). ADHs of the tested bacteria strongly preferred NAD as a cofactor. Marked ADH activities were found in all bacteria, even at low ethanol concentrations (1.5 mM) that may occur in the colon due to bacterial fermentation. The Km for ethanol varied from 29.9 mM for K. pneumoniae to 0.06 mM for Hafnia alvei. The inhibition of ADH by 4-methylpyrazole was found to be of the competitive type in 4 of 5 bacteria, and Ki varied from 18.26 +/- 3.3 mM for Escherichia coli to 0.47 +/- 0.13 mM for K. pneumoniae. At pH 7.4, ADH activity was significantly lower than at pH 9.6 in four bacterial strains. ADH of K. oxytoca, however, showed almost equal activities at neutral pH and at 9.6. In conclusion, NAD-linked alcohol dehydrogenases of aerobic colonic bacteria possess low apparent Km's for ethanol. Accordingly, they may oxidize moderate amounts of ethanol ingested during social drinking with nearly maximal velocity. This may result in the marked production of intracolonic acetaldehyde. Kinetic characteristics of the bacterial enzymes may enable some of them to produce acetaldehyde even from endogenous ethanol formed by other bacteria via alcoholic fermentation. The microbial ADHs were inhibited by 4-methylpyrazole by the same competitive inhibition as hepatic ADH, however, with nearly 1000 times lower susceptibility. Individual variations in human colonic flora may thus contribute to the risk of alcohol-related gastrointestinal morbidity, such as diarrhea, colon polyps and cancer, and liver injury.
 ...
PMID:Characteristics of alcohol dehydrogenases of certain aerobic bacteria representing human colonic flora. 916 10


<< Previous 1 2 3 4 5 6 7 Next >>