Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Single-read sequence analysis of the termini of eight randomly picked clones of Ashbya gossypii genomic DNA revealed seven sequences with homology to Saccharomyces cerevisiae genes (15% to 69% on the amino acid level). One of these sequences appeared to code for the carboxy-terminus of threonine synthase, the product of the S. cerevisiae THR4 gene (52.4% identity over 82 amino acids). We cloned and sequenced the complete putative AgTHR4 gene of A. gossypii. It comprises 512 codons, two less than the S. cerevisiae THR4 gene. Overall identity at the amino acid sequence level is 67.4%. A continuous stretch of 32 amino acids displaying complete identity between these two fungal threonine synthases presumably contains the pyridoxal phosphate attachment site. Disruption of the A. gossypii gene led to threonine auxotrophy, which could be complemented by transformation with replicating plasmids carrying the AgTHR4 gene and various S. cerevisiae ARS elements. Using these plasmids only very weak complementation of a S. cerevisiae thr4 mutation was observed. Investigation of sequences adjacent to the AgTHR4 gene identified three additional ORFs. Surprisingly, the order and orientation of these four ORFs is conserved in A. gossypii and S. cerevisiae.
Mol Gen Genet 1996 Jan 15
PMID:AgTHR4, a new selection marker for transformation of the filamentous fungus Ashbya gossypii, maps in a four-gene cluster that is conserved between A. gossypii and Saccharomyces cerevisiae. 856 89

We extended our previous study with 3'-azido-3'-deoxythymidine nucleotides [Proc. Natl. Acad. Sci. USA 91:5771-5775 (1994)] and examined the effects on human immunodeficiency virus type 1 (HIV-1) integrase of the nucleotides of three nucleoside analogues currently under evaluation in clinical trials: beta-D-2',3'-didehydro-3'-deoxythymidine, beta-D-2'-ara-fluoro-2', 3'-dideoxyadenosine, and beta-L-2',3'-dideoxy-3'-thiacytidine. Beta-D-2',3'-Didehydro-3'-deoxythymidine and beta-D-2'-ara-fluoro-2',3'-dideoxyadenosine nucleotides had IC50 values for strand transfer of 100 and 200 microM, respectively, whereas the corresponding 2',3'-dideoxynucleoside triphosphates, ddT triphosphate and ddA triphosphate, did not inhibit the integrase at 800 and 200 microM, respectively. Beta-L-2',3'-Dideoxy-3'-thiacytidine triphosphate had no effect up to 500 microM. The L-enantiomers of 5-fluoro-2',3'-dideoxycytidine monophosphate and triphosphate had IC50 values of approximately 40 microM, whereas their D-enantiomer isomers showed no inhibition at 200 microM. NAD, pyridoxal phosphate, and coumermycin A1, which exhibit no antiviral activity but are typically used to probe nucleotide binding sites, were also tested. NAD was inactive, and its etheno derivative exhibited activity at 1 mM. In contrast, pyridoxal phosphate (IC50 = 18 microM and coumermycin A1 (IC50 = 5 microM were potent inhibitors. None of the coumermycin monomeric derivatives were active integrase inhibitors. The physiological ribonucleotides ATP and GTP inhibited HIV-1 integrase at or near cellular concentrations, suggesting that they may regulate HIV-1 integrase activity in cells. In general, the active nucleotides tested inhibited binding of HIV-1 integrase to its substrate DNA an inhibited an integrase deletion mutant containing only amino acids 50-212, indicating that nucleotides bind to the enzyme catalytic core. Consisently, the choice of nucleophile in the 3'-processing reaction was blocked to the same extent regardless of the nucleotide used (water, glycerol, or the viral DNA hydroxyl) by the enzyme. These observations suggest new strategies for antiviral drug development that could be based on nucleotide analogues as inhibitors of HIV-1 integrase.
Mol Pharmacol 1996 Apr
PMID:Effects of nucleotide analogues on human immunodeficiency virus type 1 integrase. 860 89

In this paper we describe the purification of L-DOPA decarboxylase (DDC) to homogeneity from the developmental stage just before the eclosion (pharate pupae) of Ceratitis capitata. The enzyme was found to have a mol wt of approximately 100,000 and to be composed of two identical subunits (50,000 mol wt each). Polyclonal antibodies raised against the isolated enzyme reacted with the 50,000 dalton subunit and precipitated enzyme activity. Furthermore, properties of the enzyme isolated from the pharate pupa stage, were compared with those of DDC purified from the white prepupa stage with respect to substrate specificity, response to polyclonal antibodies, behaviour towards different cations and dependence of enzyme activity on the concentration of pyridoxal phosphate.
Comp Biochem Physiol B Biochem Mol Biol 1996 Feb
PMID:Purification and characterisation of L-DOPA decarboxylase from pharate pupae of Ceratitis capitata. A comparison with the enzyme purified from the white prepupae. 865 78

Band 3 protein is a typical polytropic membrane protein and mediates the exchange of the cellular HCO3- with CI- in plasma, which has been known as the "Chloride Shift". Owing to the "Chloride Shift", red blood cells can discriminate the metabolically active cells from inactive cells and deliver oxygen particularly to metabolically active tissues that produce carbon dioxide. Thus, band 3 protein is a sensor for metabolically active tissues and no excess oxygen is supplied to tissues as far as oxygen is delivered by red blood cells. In this chapter, we review the physiological role of the anion exchange mediated by band 3 protein and our work concerning the structure and function relationship in band 3 protein, that, is, affinity labeling of the active center for the anion exchange with pyridoxal phosphate, conformational change during the anion exchange process, examination of fidelity of hydropathy prediction on band 3 protein, and phosphoenolpyruvate transport mediated by band 3 protein and its clinical application.
Cell Mol Biol (Noisy-le-grand) 1996 Nov
PMID:Band 3 protein: physiology, function and structure. 896 Jul 78

A cDNA clone, CGS1, encoding cystathionine gamma-synthase (CGS) from Arabidopsis thaliana was selected by complementation of CGS mutant strain of Escherichia coli (metB). Cells expressing CGS1 can grow on medium lacking Met and contain CGS enzyme activity. Genomic DNA blot analysis of A. thaliana revealed that there is a single gene homologous with CGS1. A genomic fragment carrying CGS1 was cloned and sequenced. Through combined analysis of the cDNA and genomic clone it was determined that the CGS1 coding sequence is 1692 bp, encodes a 563 amino acid, 60 kDa protein, and is interrupted by ten introns. A transcriptional initiation site was detected 260 bp 5' of the initiator codon. The predicted amino acid sequence of CGS1 contains a consensus pyridoxal phosphate-binding site and is similar to MetB of E. coli, with which it is 35 percent identical. The CGS1 product has a sequence at the amino terminus that resembles a transit peptide for localization to plastids. At least 160 amino acids from the amino terminus of the CGS1 enzyme are not essential for enzymatic activity.
Plant Mol Biol 1996 Dec
PMID:Cloning and analysis of the gene for cystathionine gamma-synthase from Arabidopsis thaliana. 900 10

Degradation of a protein via the ubiquitin proteolytic pathway involves two successive steps. Covalent attachment of ubiquitin to the target protein and degradation of the tagged substrate by the 26S proteasome. Most native cellular proteins that are targeted by the ubiquitin system are short-lived transcriptional activators and growth and cell cycle regulators, as well as unstable membrane proteins. In the present study we demonstrate the involvement of the system in the degradation of tyrosine aminotransferase (TAT), a key enzyme in intermediary metabolism. In vitro, we have shown that the native enzyme is conjugated and degraded in a system that requires ATP and ubiquitin. Degradation was monitored by following the decrease of catalytic activity as well as disappearance of the protein molecule. The enzyme could be protected from degradation by association with its specific cofactor, pyridoxal phosphate (PLP). In vivo, we prepared cell extracts from livers of animals in which TAT was induced by starvation and corticosteroid administration. The dramatic increase in the level of the enzyme was accompanied by a concomitant increase in the level of specific TAT-ubiquitin adducts.
Mol Biol Rep 1997 Mar
PMID:Ubiquitin-mediated degradation of tyrosine aminotransferase (TAT) in vitro and in vivo. 922 77

A cluster of genes involved in the production of phaseolotoxin, a phytotoxin produced by Pseudomonas syringae pv. phaseolicola, contains eight (phtA through phtH) complementation groups (Y. X. Zhang, K. B. Rowley, and S. S. Patil, J. Bacteriol., 175:6451-6458, 1993). In this study, sequencing of the region encompassing the phtE locus revealed six putative open reading frames (ORFs), each preceded by a putative ribosomal binding site, and all oriented in the same direction. Reverse transcription-polymerase chain reaction suggested that the phtE locus is transcribed as one large (6.4 kb) transcript, indicating that the ORFs constitute an operon. Primer extension analysis showed that the transcript begins at a T, located 31 bp upstream of the ATG codon of ORF1. Comparison of the sequences of the putative ORFs with the sequences of known genes revealed that ORF3, encoding a protein containing 395 amino acids, has 55% similarity to the acetylornithine aminotransferase gene from Escherichia coli, and the ornithine aminotransferase genes from other organisms. A lysine residue that is a binding site for pyridoxal phosphate and an arginine residue that is a binding site for the alpha-carboxylate group of the substrate are conserved in ORF3. These data suggest that ORF3 encodes a protein involved in the biosynthesis of ornithine, a constituent of phaseolotoxin. ORF5, encoding a peptide of 378 amino acid residues, possesses a helix-turn-helix motif at the C-terminal end that is characteristic of the AraC family of transcriptional factors, and there is a possible leucine zipper at the N-terminal end of this peptide. ORF6, encoding a protein of 327 amino acids, has about 40% similarity with the fatty acid desaturase gene, desA, of Synechocystis Pcc6803 and considerable similarity with fatty acid desaturase genes from other organisms. ORF6 and desA show very similar hydropathy profiles and both contain a copper binding signature. Computer searches did not discover significant homologies in the data base for the other ORFs, but hydropathy analysis showed that all of them contain one to several hydrophobic domains, suggesting that the gene products of these ORFs may be membrane associated.
Mol Plant Microbe Interact 1997 Nov
PMID:The phtE locus in the phaseolotoxin gene cluster has ORFs with homologies to genes encoding amino acid transferases, the AraC family of transcriptional factors, and fatty acid desaturases. 935 42

The moderately pyridoxine (vitamin B6)-deficient male rat was introduced by us as an animal model (B6DHT) for the study of hypertension. Hypertension in this rat is associated with increased sympathetic stimulation. Arterial segments from B6DHT rats maintained a higher resting tone. The influx of 45calcium into intracellular compartment of the vascular smooth muscle of the caudate artery of B6DHT rats was also enhanced. Administration of pyridoxine attenuated the hypertension in B6DHT rats as well as in genetic or dietary-induced moderately hypertensive conditions such as in the Zucker obese rat and sucrose or low calcium-fed rats. However, pyridoxine did not have any effect on the spontaneously hypertensive rat. All classes of calcium channel blockers were effective in lowering the systolic blood pressure of B6DHT rats. The increased in vitro influx of 45calcium into intracellular compartment of artery segments of B6DHT rats as well as the BAY K 8644-induced influx of 45calcium into artery segments from normal rats were blocked by pyridoxal phosphate as well as by dihydropyridine-sensitive calcium channel blockers (DHP). Pyridoxal phosphate (PLP) in vitro enhances the binding of calcium channel antagonists to membrane preparations from vascular tissue. PLP corrects the membrane abnormality in responsive hypertensive conditions and thus, could be an endogenous modulator of DHP-sensitive calcium channels.
Mol Cell Biochem 1998 Nov
PMID:Hypertension, calcium channel and pyridoxine (vitamin B6). 982 19

Sequence determination of a region downstream from the vanXYc gene in Enterococcus gallinarum BM4174 revealed an open reading frame, designated vanT, that encodes a 698-amino-acid polypeptide with an amino-terminal domain containing 10 predicted transmembrane segments. The protein contained a highly conserved pyridoxal phosphate attachment site in the C-terminal domain, typical of alanine racemases. The protein was overexpressed in Escherichia coli, and serine racemase activity was detected in the membrane but not in the cytoplasmic fraction after centrifugation of sonicated cells, whereas alanine racemase activity was located almost exclusively in the cytoplasm. When the protein was overexpressed as a polypeptide lacking the predicted transmembrane domain, serine racemase activity was detected in the cytoplasm. The serine racemase activity was partially (64%) inhibited by D-cycloserine, whereas host alanine racemase activity was almost totally inhibited (97%). Serine racemase activity was also detected in membrane preparations of constitutively vancomycin-resistant E. gallinarum BM4174 but not in BM4175, in which insertional inactivation of the vanC-1 D-Ala:D-Ser ligase gene probably had a polar effect on expression of the vanXYc and vanT genes. Comparative modelling of the deduced C-terminal domain was based on the alignment of VanT with the Air alanine racemase from Bacillus stearothermophilus. The model revealed that almost all critical amino acids in the active site of Air were conserved in VanT, indicating that the C-terminal domain of VanT is likely to adopt a three-dimensional structure similar to that of Air and that the protein could exist as a dimer. These results indicate that the source of D-serine for peptidoglycan synthesis in vancomycin-resistant enterococci expressing the VanC phenotype involves racemization of L- to D-serine by a membrane-bound serine racemase.
Mol Microbiol 1999 Mar
PMID:Characterization and modelling of VanT: a novel, membrane-bound, serine racemase from vancomycin-resistant Enterococcus gallinarum BM4174. 1020 40

The availability of genome sequences, affordable mass spectrometers and high-resolution two-dimensional gels has made possible the identification of hundreds of proteins from many organisms by peptide mass fingerprinting. However, little attention has been paid to how information generated by these means can be utilised for detailed protein characterisation. Here we present an approach for the systematic characterisation of proteins using mass spectrometry and a software tool FindMod. This tool, available on the internet at http://www.expasy.ch/sprot/findmod.html , examines peptide mass fingerprinting data for mass differences between empirical and theoretical peptides. Where mass differences correspond to a post-translational modification, intelligent rules are applied to predict the amino acids in the peptide, if any, that might carry the modification. FindMod rules were constructed by examining 5153 incidences of post-translational modifications documented in the SWISS-PROT database, and for the 22 post-translational modifications currently considered (acetylation, amidation, biotinylation, C-mannosylation, deamidation, flavinylation, farnesylation, formylation, geranyl-geranylation, gamma-carboxyglutamic acids, hydroxylation, lipoylation, methylation, myristoylation, N -acyl diglyceride (tripalmitate), O-GlcNAc, palmitoylation, phosphorylation, pyridoxal phosphate, phospho-pantetheine, pyrrolidone carboxylic acid, sulphation) a total of 29 different rules were made. These consider which amino acids can carry a modification, whether the modification occurs on N-terminal, C-terminal or internal amino acids, and the type of organisms on which the modification can be found. We illustrate the utility of the approach with proteins from 2-D gels of Escherichia coli and sheep wool, where post-translational modifications predicted by FindMod were confirmed by MALDI post-source decay peptide fragmentation. As the approach is amenable to automation, it presents a potentially large-scale means of protein characterisation in proteome projects.
J Mol Biol 1999 Jun 11
PMID:High-throughput mass spectrometric discovery of protein post-translational modifications. 1035 35


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