Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.6.1.3 (ATPase)
65,361 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The adeno-associated virus (AAV) Rep protein is required for both viral DNA replication and transactivation of the AAV promoters. Here we report the effects of mutations in the rep gene on transcription and replication in vivo and terminal repeat binding and terminal resolution site (trs) endonuclease activities in vitro. In all, we examined 10 in-frame deletions and 14 amino acid substitution mutations at eight positions. The point mutations were targeted to regions that are highly conserved among the parvovirus nonstructural proteins and include the extended ATPase domain of the AAV Rep protein. The mutations identify at least two noncontiguous regions of Rep which are essential for terminal repeat binding (amino acids 134 to 242 and amino acids 415 to 490). Mutations in either region render the protein inactive for both DNA replication and transactivation. In addition, mutations within a putative ATPase region also cause defects in replication and transactivation in vivo as well as in the ATP-dependent trs endonuclease activity in vitro. These results suggest that Rep transactivates via a novel mechanism which may require both DNA binding and an enzymatic activity, namely, ATPase or DNA helicase activity.
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PMID:Analysis of mutations in adeno-associated virus Rep protein in vivo and in vitro. 131 96

It is shown that the second cholera toxin, Zot, ORF3 product of Pseudomonas plasmid pKB740, and ORF424 product of bacteriophage Pf1 are a group of closely related proteins containing a modified version of the purine NTP-binding motif, with a drastic substitution of tyrosine for a conserved glycine. They are distantly but reliably related to the product of gene I of filamentous bacteriophages which is a putative ATPase containing the classical NTP-binding motif and is involved in bacteriophage assembly and exit from the bacterial cell. Hydropathy analysis suggests that the Zot and gene I product may have a similar transmembrane topology. It is hypothesized that Zot may possess ATPase activity and modify the membrane structure of its target cells in an ATP-dependent fashion. Genes for Zot and the related protein of pKB740 are likely to have evolved from gene I of a Pf1-like bacteriophage.
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PMID:The second cholera toxin, Zot, and its plasmid-encoded and phage-encoded homologues constitute a group of putative ATPases with an altered purine NTP-binding motif. 142 34

A putative ATPase gene was cloned from Trypanosoma brucei genomic DNA. The length of the gene open reading frame is 3,033 bp, predicting a protein of about 110 kDa. The sequence of this protein shares 10 blocks of homology with other eukaryotic ATPases, including the putative phosphorylation site characteristic of P-ATPases. Its hydropathy profile reveals 8-10 potential membrane-spanning regions. While the amino acid sequence of the T. brucei ATPase shows only 25% overall homology with its counterpart from the related kinetoplastid protozoan Leishmania donovani, 49% sequence conservation is found when compared with the calcium-ATPase from rabbit sarcoplasmic reticulum. This gene is present in only one copy, localized in the large chromosome fraction. It is transcribed at a similar level in procyclic and bloodstream forms, as a 4.3-kb mRNA. Run-on assays suggest continuous transcription of the gene and flanking sequences over at least 10 kb, by a RNA polymerase sensitive to alpha-amanitin. Transcription inhibition by UV irradiation suggests that the ATPase gene is more than 4 kb downstream from its promoter.
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PMID:Structure and transcription of a P-ATPase gene from Trypanosoma brucei. 183 43

The genome of the hepatitis C virus directs the synthesis of a single polyprotein, which is proteolytically cleaved into at least nine functional proteins. The amino-terminal portion of the polyprotein forms the structural proteins, while the carboxy-terminal region constitutes a variety of viral enzymes. The nonstructural 3 (NS3) protein, consisting of amino acids 1027-1657 of the polyprotein, is believed to be a multifunctional protein with an amino-terminal serine protease domain, which is involved in polyprotein processing, and a carboxy-terminal ATPase/RNA helicase domain, presumably involved in viral replication. We have assembled an expression vector which directs the synthesis of residues 1207-1612 of the polyprotein with an amino-terminal polyhistidine purification tag. This portion of the NS3 protein contains the putative ATPase/helicase domain. The protein has been purified to yield 30-50 mg of enzymatically active protein per liter of culture. The purified NS3 protein has both NTPase and RNA helicase activities. ATP is the preferred substrate for the NTPase; GTP is also utilized; however, UTP is a very poor substrate and CTP is not utilized. The RNA helicase activity is dependent on ATP and divalent cation. Either manganese or magnesium can serve as the divalent cation.
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PMID:Expression, isolation, and characterization of the hepatitis C virus ATPase/RNA helicase. 748 72

The cloning, expression, and biochemical characterization of an essential gene of Saccharomyces cerevisiae that encodes for a new member of the TBP1-like subfamily of putative ATPases are described. The protein is 72% identical at the amino acid level to subunit four (S4) of the human 26 S protease and 73% identical to Schizosaccharomyces pombe MTS2 gene product. The purified, recombinant protein, designated Yhs4p, has an estimated molecular mass of 49 kDa and exhibits a Mg(2+)-dependent ATPase activity with nucleotide specificity and Km for ATP similar to those exhibited by the human 26 S protease. The observed ATPase activity was reduced by 73% upon the introduction of point mutation K229Q in the "P-loop" domain of the ATP-binding site relative to the nonmutated form of the protein. This is the first direct biochemical evidence supporting the putative ATPase activity of a member of the TBP1-like subfamily. Furthermore, the experimental results demonstrate a regulatory function for the amino-terminal region of the molecule. The amino-terminal truncated form of Yhs4p lacking two clusters of positively charged amino acids exhibits a greater ATPase activity. The ATPase activity of both the truncated and complete forms of Yhs4p is stimulated by polyanions. Polylysine partially inhibits the ATPase activity of the amino-terminal truncated form having no observable effect on the complete protein. N-Ethylmaleimide inhibits the ATPase activity of both forms of Yhs4p. We propose that Yhs4p ATPase may play an essential role in the regulatory function of the proteolytic activity of the yeast 26 S protease.
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PMID:Cloning and expression of a yeast gene encoding a protein with ATPase activity and high identity to the subunit 4 of the human 26 S protease. 772 33

Wilson disease (WD) is an autosomal recessive disorder of copper transport, resulting in copper accumulation and toxicity to the liver and brain. The gene (WD) has been mapped to chromosome 13 q14.3. On yeast artificial chromosomes from this region we have identified a sequence, similar to that coding for the proposed copper binding regions of the putative ATPase gene (MNK) defective in Menkes disease. We show that this sequence forms part of a P-type ATPase gene (referred to here as Wc1) that is very similar to MNK, with six putative metal binding regions similar to those found in prokaryotic heavy metal transporters. The gene, expressed in liver and kidney, lies within a 300 kb region likely to include the WD locus. Two WD patients were found to be homozygous for a seven base deletion within the coding region of Wc1. Wc1 is proposed as the gene for WD.
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PMID:The Wilson disease gene is a putative copper transporting P-type ATPase similar to the Menkes gene. 829 39

Vaccinia virus early transcription factor (VETF) activates the transcription of early gene templates by the viral RNA polymerase. VETF is a heterodimeric protein that binds to transcription promoters and has an associated DNA-dependent ATPase activity. The small subunit of VETF has sequences resembling two motifs commonly found in ATPases: an A-type ATP binding motif and a DEAH box. To investigate the functional role of the ATPase activity, we have analyzed the effect of mutations in each of the putative ATPase motifs. Recombinant VETF was expressed in HeLa cells using a vaccinia virus/T7 RNA polymerase system. Simultaneous expression of both subunits of VETF was required to obtain soluble protein with promoter binding, DNA-dependent ATPase, and transcription activation functions. The mutants with altered ATPase motifs retained promoter binding activity but had no detectable ATPase activity and no ability to activate transcription. The DEAH box mutant was shown to dominantly repress transcription activation by wildtype VETF. These results indicate that the DNA-dependent ATPase activity of VETF is essential for its transcription activation function.
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PMID:The DNA-dependent ATPase activity of vaccinia virus early gene transcription factor is essential for its transcription activation function. 837 62

Isolated membranes of the moderate halophilic bacterium Haloferax volcanii are able to hydrolyze ATP via an ATPase, which needs the presence of Mg2+ or Mn2+, high concentrations of NaCl, a pH value of 9, and high temperatures with an optimum at 60 degrees C. We have not found any phosphatase activity in the preparations. We developed a purification method for the isolated enzyme with an enrichment factor of 90. SDS-gel electrophoresis of the partially purified enzyme of Haloferax volcanii showed putative ATPase subunits of 63, 51, 37, and 12 kDa. N-ethylmaleimide (NEM) a specific inhibitor for V-ATPases, which alkylates cyteines, inhibited the enzyme slightly. Binding of tritiated NEM to the isolated ATPase fractions resulted in labelling of the 63 and 51 kDa peptides. Using PCR with degenerate oligonucleotides, we could clone and sequence a gene cluster encoding the A1 part of the halophilic ATPase. The described genes are organized in an operon in the order D, C, E, B, A, named alphabetically according to their decreasing size. The deduced products of 64.5, 52, 38.7, 22, and 11.6 kDa confirm the results of the partial purification of the ATPase. Biochemical characterization of the Haloferax volcanii ATPase gave the following results: In presence of Mn2+ higher rates of ATP hydrolysis could be observed than in presence of Mg2+, but free manganese ions inhibited the enzyme activity of the ATPase. Calculation of the true concentrations of the complex between ATP and the respective divalent metal ion led to determination of Michaelis-Menten constants for ATP in the hydrolysis direction of 1 mM in presence of MgCl2 and 0.24 mM in presence of MnCl2. Sodium chloride concentrations in the molar range induce changes in KM by a factor of about 10. The enzyme is specific for ATP; other nucleotides including GTP and ADP are competitive inhibitors of ATP hydrolysis.
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PMID:Isolation, characterization, and substrate specificity of the plasma membrane ATPase of the hlophilic achaeon Haloferax volcanii. 872 Dec 12

In this study, we isolated and sequenced a Helicobacter pylori gene, designated ftsH, coding for a 632-amino-acid protein which displayed striking similarity throughout its full length to FtsH proteins identified in Escherichia coli, Lactococcus lactis, and Bacillus subtilis. H. pylori FtsH also possessed approximately 200-amino-acid region containing a putative ATPase module which is conserved among members of the AAA protein family (AAA, ATPase associated with diverse cellular activities). The H. pylori ftsH product was overexpressed in E. coli and reacted immunologically with an anti-E. coli FtsH serum (T. Tomoyasu, K. Yamanaka, K. Murata, T. Suzaki, P. Bouloc, A. Kato, H. Niki, S. Hiraga, and T. Ogura, J. Bacteriol. 175:1352-1357, 1993). FtsH was also shown to be present in the membrane fraction of H. pylori, suggesting that it is membrane bound. Disruption of the ftsH gene led to the loss of viability of H. pylori, demonstrating that this gene is essential for cell growth. Overproduction of both H. pylori FtsH and E. coli FtsH together tremendously reduced the growth rate of the E. coli host cells, whereas the growth of the E. coli cells carrying the wild-type E. coli ftsH operon on the chromosome was not significantly affected by overproduction of H. pylori FtsH itself. This result suggests that the abnormal growth of cells results from interaction between H. pylori FtsH and E. coli FtsH.
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PMID:Sequencing, expression, and genetic characterization of the Helicobacter pylori ftsH gene encoding a protein homologous to members of a novel putative ATPase family. 889 13

SUG1 is an integral component of the 26 S proteasome. Belonging to a novel putative ATPase family, it shares four conserved motifs characteristic of ATP-dependent DNA/RNA helicases. Recombinant rat SUG1 (rSUG1) produced in Escherichia coli was highly purified and characterized in terms of its biochemical properties. The rSUG1 exhibited a Mg2+-dependent ATPase activity. The Km for ATP and Vmax of rSUG1 were 35 microM and 7 pmol of ATP/min/microg of protein, respectively. Both ATPase activity to release [32P]monophosphate and [32P]ATP-labeling activity were coordinately affected by cold ATP severely, GTP and UTP moderately, and CTP little. Interestingly, the rSUG1 ATPase activity was stimulated by poly(U) and poly(C), but not by poly(A), poly(G), or by any forms of DNAs tested. A UV cross-linking assay also indicated poly(U)- and poly(C)-stimulated labeling of rSUG1 with [alpha-32P]ATP. Moreover, the ATPase activity was facilitated by cellular poly(A)+ RNA, but not by poly(A)- RNA. RNA transcribed in vitro from cDNA encoding a b-Zip protein could stimulate the ATPase activity. This is the first report to demonstrate a specific RNA requirement for ATPase with respect to the proteasomal ATPases. Our present work suggests that SUG1 can specifically interact with protein-coding RNA (mRNA) and play some roles in mRNA metabolism.
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PMID:SUG1, a component of the 26 S proteasome, is an ATPase stimulated by specific RNAs. 928 26


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