Disease relevance of poxB

• Complete cross-reactivity was found with antibodies directed against the pyruvate dehydrogenase complex from E. coli and electron micrographs of both enzyme complexes reveal identical structures [1].
• The gene was named poxB for Pseudomonas oxacillinase [2].
• HLA DRB4 0101-restricted immunodominant T cell autoepitope of pyruvate dehydrogenase complex in primary biliary cirrhosis: evidence of molecular mimicry in human autoimmune diseases [3].
• Expression in Escherichia coli of genes encoding the E1 alpha and E1 beta subunits of the pyruvate dehydrogenase complex of Bacillus stearothermophilus and assembly of a functional E1 component (alpha 2 beta 2) in vitro [4].
• Expression cloning and demonstration of Enterococcus faecalis lipoamidase (pyruvate dehydrogenase inactivase) as a Ser-Ser-Lys triad amidohydrolase [5].

High impact information on poxB

• Each polypeptide chain in the lipoate acetyltransferase (E2) core of the pyruvate dehydrogenase complex from Escherichia coli contains three repeating sequences in the N-terminal half of the molecule [6].
• Rabbit antiserum to the dihydrolipoamide dehydrogenase (dihydrolipoamide:NAD+ oxidoreductase, EC 1.8.1.4) component of the pyruvate dehydrogenase complex from bakers' yeast was used to screen plaques produced by a lambda gt11 yeast cDNA library [7].
• A computer model analysis of the active-site coupling mechanism in the pyruvate dehydrogenase multienzyme complex of Escherichia coli [8].
• Thus, with a functional assay that depends on epitope recognition of primary biliary cirrhosis sera, cross-reactivity between mammalian and bacterial pyruvate dehydrogenase complex enzymes is low and molecular mimicry, at least at the B-lymphocyte level, is not supported [9].
• Antibodies reacting with the E2 polypeptides of the 2-oxoglutarate dehydrogenase complex and branched-chain 2-oxo acid dehydrogenase complex show some cross-reactivity but do not recognize any of the antigens of the pyruvate dehydrogenase complex [10].

Chemical compound and disease context of poxB

• An E. coli mutant defective in poxB, the structural gene encoding pyruvate oxidase, did not have these phenotypes; therefore, they are not solely a consequence of a pyruvate oxidase deficiency [11].
• The deduced amino acid sequence shows good homology to the sequence of lipoamide dehydrogenase associated with the pyruvate dehydrogenase complex from Escherichia coli, yeast, and humans [12].
• We also found that the transketolases are related to another vitamin B1-dependent enzyme: the E1 subunit of pyruvate dehydrogenase from Escherichia coli [13].
• Regulatory properties of the pyruvate dehydrogenase complex from Escherichia coli. Studies on the thiamin diphosphate-dependent lag phase [14].
• Pyruvate dehydrogenase complex of Escherichia coli. Thiamin pyrophosphate and NADH-dependent hydrolysis of acetyl-CoA [15].

Biological context of poxB

• Genetic and biochemical analyses of the mutant revealed the downregulation of many TCA cycle enzymes, including citrate synthase, and the upregulation of the pyruvate dehydrogenase complex in both transcription and enzyme activities [16].
• The presence of PYC in a poxB mutant resulted in a 42% lower maintenance coefficient and a 42% greater biomass yield compared to the wildtype [17].
• Furthermore, the influence of the poxB gene knockout on the growth of E. coli was also studied because of its similar function to PDHc which connects the glycolysis to the TCA cycle [18].
• The entire nucleotide sequence of the poxB (pyruvate oxidase) gene of Escherichia coli K-12 has been determined by the dideoxynucleotide (Sanger) sequencing of fragments of the gene cloned into a phage M13 vector [19].
• The promoter region of poxB, the structural gene for pyruvate oxidase, which is also under the control of sigma S and cAMP-CRP, is very similar to the corresponding region of csiE, suggesting a similar regulatory mechanism also for poxB [20].

Anatomical context of poxB

• A new metabolic link. The acyl carrier protein of lipid synthesis donates lipoic acid to the pyruvate dehydrogenase complex in Escherichia coli and mitochondria [21].
• A substantial fraction of the E2 protein as well as part of the pyruvate dehydrogenase enzymatic activity was associated with the cytoplasmic membrane in A. laidlawii [22].
• Tissue-specific and developmental-specific expression of an Arabidopsis thaliana gene encoding the lipoamide dehydrogenase component of the plastid pyruvate dehydrogenase complex [23].
• Induced genes were numerous in groups specifying the degradation of small molecules (carbon compounds, amino acids and fatty acids), energy metabolism (aerobic and anaerobic respiration, pyruvate dehydrogenase and TCA cycle), chemotaxis and mobility, flagella biosynthesis, surface structures and phage related functions [24].
• It is preceded by the gene encoding the pyruvate dehydrogenase component (E1) of pyruvate dehydrogenase complex and by an intercistronic region of 11 base pairs containing a good ribosome binding site [25].

Associations of poxB with chemical compounds

• Reassociation to a fully active complex molecule works with equal facility between the pyruvate dehydrogenase component and a dihydrolipoamide transacetylase: dihydrolipoamide dehydrogenase subcomplex from either organism in all possible combinations [1].
• Strain YYC202 (aceEF pfl poxB pps) generated 90 g/liter lactate in 16 h during the anaerobic phase (with a yield of 0.95 g/g and a productivity of 5.6 g/liter . h) [26].
• The malic enzyme, involved in the production of pyruvate, and pyruvate dehydrogenase, required for the channelling of pyruvate into acetyl-CoA, were also induced in IAA-treated cells [27].
• Inactivation of poxB caused a severe reduction in growth rate in strain PB11 when grown in the fermentor with medium containing glucose or glucose plus acetate, whereas under the same conditions poxB(-)derivative strains of JM101 and PB12 were not affected [28].
• The purified enzyme was found to cleave both small molecule lipoylated and biotinylated substrates as well as lipoic acid from two 2-oxoacid dehydrogenases and an isolated lipoylated lipoyl domain derived from the pyruvate dehydrogenase E2 subunit [5].

Analytical, diagnostic and therapeutic context of poxB

• Relative transcript levels for 29 genes related to poxB transcriptional regulation and central metabolism were determined using RT-PCR [28].
• The pyruvate dehydrogenase complex of Escherichia coli and subcomplexes derived from it by selective removal of component enzymes have been subjected to quaternary structural analysis by scanning transmission electron microscopy [29].
• Molecular cloning of the p45 subunit of pyruvate dehydrogenase kinase [30].
• A library of monoclonal antibodies to Escherichia coli K-12 pyruvate dehydrogenase complex. Competitive epitope mapping studies [31].
• T(2) relaxation experiments in combination with chemical shift and site-directed mutagenesis data were used to identify sites involved in weak but specific protein-protein interactions in the pyruvate dehydrogenase multienzyme complex of Bacillus stearothermophilus [32].

References