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:2.7.7.7 (DNA polymerase)
17,007 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The protective effect of Mr 70,000 heat shock protein (HSP-70) during thermotolerance has been previously observed. However, it is not known what cellular processes or components may be protected by this protein during the tolerance state. In the studies reported here, the protective effects of purified HSP-70, the nonspecific heat-stable proteins fetuin and trypsin inhibitor (ovomucoid), and other proteins and agents such as bovine serum albumin, D2O, or glycerol on protein and DNA synthesis during heating were investigated in vitro. In vitro protein synthesis at 30, 40, and 42 degrees C was measured by globin mRNA translation. Protein synthesis was inhibited 40 to 70% when incubated for 60 min at 40 and 42 degrees C. However, protein synthesis was protected when either fetuin or ovomucoid was present during protein synthesis at elevated temperatures. The protection was concentration dependent. The HSP-70 purified from Chinese hamster (HA-1) cells was also able to confer protection to the translation system, but at much lower concentrations than either fetuin or ovomucoid. Other proteins, such as bovine serum albumin, or other agents, such as D2O or glycerol which are known protectors of cellular survival during heating, did not protect the translation system. Similar experiments were performed with DNA synthesis in vitro. Purified DNA polymerase alpha was added to the activated calf thymus DNA in an in vitro replication system. A temperature of 46 degrees C for 60 min inhibited replication by 40%. Addition of heat-stable proteins, purified HSP-70, bovine serum albumin, D2O, or glycerol did not confer protection to the replication system. These studies provide new evidence that HSP-70 may confer protection to a component of the protein synthesis machinery during thermotolerance.
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PMID:Effects of heat shock proteins (Mr 70,000) on protein and DNA synthesis at elevated temperatures in vitro. 246 56

The purpose of this paper was to study the gamma delta T-cell receptor repertoire and target specificity following stimulation of peripheral T cells of BALB/c mice with autologous or bacterial ligands. The expression of V gamma and V delta chain families in T cells that had been expanded by stimulation in syngeneic mixed lymphocyte culture or with purified protein derivative (PPD) was determined by the semiquantitative DNA polymerase chain reaction (PCR) method. Responder T cells to either of these stimuli strongly expressed both V delta 5 and V delta 6 genes. However, addition of the ML 30 anti-murine heat shock protein (hsp) 60 monoclonal antibody (mAb) to the cell culture selectively inhibited only the expansion of V delta 5 T cells. A V delta 5 T-cell hybridoma (KMT-5), which recognized syngeneic splenic and fibrosarcoma Meth A cells but not allogeneic cells, was produced by cell fusion from autoreactive blast cells. Incubation of the KMT-5 hybridoma in the presence of ML 30 antibody blocked the stimulation of interleukin-2 (IL-2) secretion by syngeneic target cells. It was also found that the DNA of KMT-5 hybridoma and of the autoreactive gamma delta T cells contained the BALB/c invariant delta (BID) chain sequence. It is concluded from these results that BALB/c peripheral V delta 5 T cells recognize an autologous hsp 60 target specificity in a V delta-gene restricted manner. We also propose that T cells of this V gene family may be involved in the immune surveillance of certain tumours and intracellular infections.
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PMID:V delta 5+ T cells of BALB/c mice recognize the murine heat shock protein 60 target cell specificity. 790 91

A complete life cycle for the ubiquitous protozoan parasite Toxoplasma was proposed over 25 years ago. Since that time, despite attempts to make the genus polyspecific, there has been only one species, Toxoplasma gondii, consistently recognised in the genus. Recent studies on taxa in genera closely related to Toxoplasma such as Neospora, Hammondia, Frenkelia, Isospora and Sarcocystis, have convincingly showed the need for a reclassification of many of the species in these genera. However, in addition to these genus level studies, over the last 10 years several laboratories have used molecular techniques including isoenzyme electrophoresis, restriction fragment length polymorphism analyses, random amplified polymorphic DNA - polymerase chain reaction, and comparisons of the small subunit ribosomal RNA gene, DNA polymerase alpha intron, and 70 kDa heat shock protein gene nucleotide sequences to investigate the genetic diversity among strains in the species T. gondii. Overall, the results of these analyses confirm that the strains in the genus Toxoplasma comprise a limited number of clonal lineages, directly correlated with their virulence in mice. The aim of this presentation is to review the molecular research in this area in order to raise the hypothesis that there may be more than one species in the genus Toxoplasma, which may contain taxa with distinct and different life cycles.
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PMID:Is there more than one species in the genus Toxoplasma?? 1062 36

We report the complete sequence of cosmid c18A7 (41 046 bp insert), located on the right arm of chromosome II of the Schizosaccharomyces pombe genome. The sequence, which partially overlaps with cosmids SPBC4F6 and SPBC336, contains 16 open reading frames (ORFs) capable of coding for proteins of at least 100 amino acid residues in length (one partial) and one small nucleolar RNA (snoRNA). Four known genes were found: swi10 (encoding a mating-type switching protein also involved in nucleotide excision repair); dim1 (encoding a dimethyladenosine transferase); arf1 (encoding ADP-ribosylation factor 1); and pol3 (cdc6) the partial fragment, encoding the 125 kDa catalytic subunit of the DNA polymerase type B. Six ORFs similar to known proteins were found. They include a transporter of the major facilitator superfamily class, a vacuolar sorting protein, an asparagine synthase, a nuclear protein, a reticulum oxidoreductin and a heat shock protein. Each protein product of the other six ORFs has conserved domains and can be assigned a molecular, but not a biological, function. The sequence has been submitted to the EMBL database under Accession No. AL080287.
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PMID:Analysis of 41 kb of the DNA sequence from the right arm of chromosome II of Schizosaccharomyces pombe. 1153 33

The incidence of platelet bacterial contamination is approximately 1 per 2,000 units and has been acknowledged as the most frequent infectious risk from transfusion. In preliminary studies, the sterility of platelet concentrates (PCs) was tested with an automated bacterial blood culturing system and molecular genetic assays. Two real-time reverse transcriptase PCR (RT-PCR) assays performed in a LightCycler instrument were developed and compared regarding specificity and sensitivity by the use of different templates to detect the majority of the clinically important bacterial species in platelets. Primers and probes specific for the conserved regions of the eubacterial 23S rRNA gene or the groEL gene (encoding the 60-kDa heat shock protein Hsp60) were designed. During the development of the 23S rRNA RT-PCR, problems caused by the contamination of reagents with bacterial DNA were noted. Treatment with 8-methoxypsoralen and UV irradiation reduced the level of contaminating DNA. The sensitivity of the assays was greatly influenced by the enzyme system which was used. With rTth DNA polymerase in a one-enzyme system, we detected 500 CFU of Escherichia coli or Staphylococcus epidermidis/ml. With a two-enzyme system consisting of Moloney murine leukemia virus RT and Taq DNA polymerase, we detected 16 CFU/ml. With groEL mRNA as the target of RT-PCR under optimized conditions, we detected 125 CFU of E. coli/ml, and no problems with false-positive results caused by reagent contamination or a cross-reaction with human nucleic acids were found. Furthermore, the use of mRNA as an indicator of viability was demonstrated. Here we report the application of novel real-time RT-PCR assays for the detection of bacterial contamination of PCs that are appropriate for transfusion services.
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PMID:Two novel real-time reverse transcriptase PCR assays for rapid detection of bacterial contamination in platelet concentrates. 1547 37

The gene encoding a small heat shock protein (sHSP) from Pyrococcus furiosus was redesigned and chemically synthesized by using bacteria-preferred codons. The gene product was over-expressed in Escherichia coli BL21(DE)(3) and purified to homogeneity. In the presence of this protein, the activities of Taq DNA polymerase, DNA restriction endonuclease HindIII and lysozyme were protected at elevated temperature, and also, thermal aggregation of lysozyme was prevented by this purified recombinant sHSP.
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PMID:Over-expression and characterization of the recombinant small heat shock protein from Pyrococcus furiosus. 1679 64

The Roseobacter clade is abundant and widespread in marine environments and plays an important role in oceanic biogeochemical cycling. In this present study, a lytic siphophage (labeled vB_DshS-R5C) infecting the strain type of Dinoroseobacter shibae named DFL12^T, which is part of the Roseobacter clade, was isolated from the oligotrophic South China Sea. Phage R5C showed a narrow host range, short latent period and low burst size. The genome length of phage R5C was 77, 874 bp with a G+C content of 61.5%. Genomic comparisons detected no genome matches in the GenBank database and phylogenetic analysis based on DNA polymerase I revealed phylogenetic features that were distinct to other phages, suggesting the novelty of R5C. Several auxiliary metabolic genes (e.g., phoH gene, heat shock protein and queuosine biosynthesis genes) were identified in the R5C genome that may be beneficial to the host and/or offer a competitive advantage for the phage. Among siphophages infecting the Roseobacter clade (roseosiphophages), four gene transfer agent-like genes were commonly located with close proximity to structural genes, suggesting that their function may be related to the tail of siphoviruses. The isolation and characterization of R5C demonstrated the high genomic and physiological diversity of roseophages as well as improved our understanding of host-phage interactions and the ecology of the marine Roseobacter.
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PMID:A Novel Roseosiphophage Isolated from the Oligotrophic South China Sea. 3139 6

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