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

---

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

The bacteriophage T4 tsL141 (A737V) mutant in T4 DNA polymerase is temperature-sensitive for DNA replication and an antimutator for some types of mutations. In the accompanying paper (Spacciapoli, P., and Nossal, N. G. (1993) J. Biol. Chem. 269, 438-446), we show that the purified A737V T4 DNA polymerase is less processive than the wild type enzyme as a polymerase, but is more processive as an exonuclease. The bacteriophage T4 multienzyme replication complex reconstituted with the A737V mutant polymerase is defective in both lagging and leading strand synthesis. On lagging strand templates, the A737V polymerase is stimulated by the gene 44/62 and 45 polymerase accessory proteins and the gene 32 DNA binding protein, but is still arrested at pause sites much more frequently than the wild type. In contrast to wild type T4 DNA polymerase, the A737V polymerase does not catalyze leading strand synthesis on a forked duplex template with the polymerase accessory proteins, 32 protein, and the gene 41 protein helicase. The A737V polymerase requires the T4 gene 59 helicase assembly protein, as well as the other proteins, to carry out this reaction. Each of these defects is suppressed by the intragenic L771F mutation that suppresses the antimutator phenotype of the A737V, polymerase in vivo (Reha-Krantz, L. J., Stocki, S., Nonay, R., and Maughan, C. (1989) J. Cell. Biochem. 13D, 140).
...
PMID:Interaction of DNA polymerase and DNA helicase within the bacteriophage T4 DNA replication complex. Leading strand synthesis by the T4 DNA polymerase mutant A737V (tsL141) requires the T4 gene 59 helicase assembly protein. 827 34

Initiation of adenovirus DNA replication in vitro minimally requires the viral TP-DNA template and the precursor terminal protein-DNA polymerase heterodimer (pTP-pol). Optimal initiation occurs in the presence of the cellular transcription factors NFI and Oct-1 and the viral DNA binding protein (DBP). We have studied the influence of these three stimulatory proteins on the kinetics of formation of the pTP-dCMP initiation complex. NFI increases the Vmax of the reaction but does not affect the apparent Km for dC-TP. This indicates that NFI acts by enlarging the amount of active initiation complex in agreement with its stabilizing effect on binding of pTP-pol to the template. Similar kinetic effects were observed for Oct-1. Since Oct-1 does not stabilize binding of pTP-pol to the origin this suggests that Oct-1 increases the rate of pTP-dCMP formation. DBP stimulates the initiation reaction in two ways. First, it moderately increases the Vmax at suboptimal NFI concentrations, which is related to its enhancing effect on binding of NFI to the origin. Second, a much larger stimulation was caused by DBP itself based on a reduction of the Km for dCTP, which was independent of the concentration of pTP-pol or NFI. The Km for dCTP during initiation is lower than during elongation.
...
PMID:The adenovirus DNA binding protein effects the kinetics of DNA replication by a mechanism distinct from NFI or Oct-1. 844 75

The purpose of this review is to summarize information published since 1990 on DNA replication, recombination and repair of vaccinia virus, a poxvirus. Temperature-sensitive mutations reveal four essential genes related to viral DNA replication: the E9L DNA polymerase, B1R protein kinase, D5R protein, and D4R uracil DNA glycosylase. Other proteins are likely to be also involved in viral DNA replication: the H6R DNA topoisomerase, I3L single stranded-DNA binding protein, H5R virosome-associated protein, and A50R DNA ligase. In addition, several viral-encoded proteins do regulate the level of the deoxyribonucleoside triphosphate pool: the J2R thymidine kinase, A48R thymidylate kinase, 14L and F4L subunits of ribonucleotide reductase, and F2L dUTPase. Despite the apparent simplicity of the mechanism of vaccinia virus DNA replication, several important questions related to the three Rs remain unsolved.
...
PMID:Vaccinia virus DNA replication: a short review. 882 74

UL9 is the origin binding protein of herpes simplex virus type-1 (HSV-1). A UL9-specific monoclonal antibody (17B) whose epitope maps to the N-terminal 33 amino acids was used to study the localization of UL9 in infected and transfected cells. We demonstrate the colocalization of UL9 and the HSV-1 single-strand DNA binding protein (ICP8 or UL29) in replication compartments, sites of viral DNA synthesis. On the other hand, UL9 does not completely colocalize with ICP8 in prereplicative sites, structures observed under conditions that inhibit viral DNA polymerase. Cells transfected with various deletion or pyruvate kinase fusion constructs were analyzed by indirect immunofluorescence assay to define the nuclear localization signal (NLS) of UL9. Deletion analysis showed that the region required for nuclear localization lies within the C-terminal DNA binding domian (amino acids 535-851). Various regions of UL9 were tested in fusion constructs for their ability to direct the normally cytoplasmic chicken pyruvate kinase protein to the nucleus. A fusion construct containing the carboxy-terminal 107 residues (amino acids 745-851) localized efficiently to the nucleus, whereas a fusion construct containing the N-terminal 660 amino acids of UL9 was unable to do so. Mutations designed to alter a potential NLS sequence (793-KREFAGARFKLR-804) within the C-terminal 107 residues result in a mutant UL9 protein which falls to localize efficiently to the nucleus. These results suggest that the major NLS of UL9 maps within the C-terminal 107 amino acids.
...
PMID:Intracellular localization of the herpes simplex virus type-1 origin binding protein, UL9. 887 99

The human adenovirus type 5 (Ad5) E2 transcription unit is divided into a promoter-proximal region, E2A, and a distal region, E2B, each with its own polyadenylation site. Together these regions encode the three virus-derived proteins necessary for genome replication. Ad5 variants were produced that carried linker insertion mutations immediately 5' and/or 3' to the coding sequence for the E2A gene DNA binding protein (DBP). Two variants carrying solely a 5' lesion showed decreased usage of the adjacent 3' splice site, via which the DBP mRNA is produced, and an increased usage of the alternative downstream splice sites in the E2B region, wherein viral DNA polymerase and terminal protein precursor are encoded; these viruses showed somewhat reduced growth. A variant carrying a 3' lesion showed a marginal increase in DBP expression and slightly accelerated growth. When lesions 5' and 3' to the DBP coding sequence were combined in cis, the resulting virus was severely defective for growth and expressed E2B products to the virtual exclusion of E2A DBP. These data indicate that interactions must occur between the E2A 3' splice site and polyadenylation site before this region can be treated as an exon by the RNA processing machinery, and that a sequence alteration at the polyadenylation site that alone has only minor effects on the pattern of RNA processing can drastically affect terminal exon usage when placed in cis with a mutation that reduces splicing efficiency at the upstream 3' splice site. The data further indicate that, in vivo, Ad5 DNA replication is limited by prevailing DBP levels rather than by levels of polymerase or terminal protein precursor.
...
PMID:Human adenovirus type 5 variants with sequence alterations flanking the E2A gene: effects on E2 expression and DNA replication. 887 22

A DNA binding protein with DNA polymerase 'accessory activity' has been identified and purified to apparent homogeneity from pea chloroplasts. This protein consists of a single subunit of 43 kDa and binds to DNA regardless of its base sequence and topology. It increases cognate DNA polymerase-primase activity in a dose dependent manner. Using solid phase protein-protein interaction trapping and co-immunoprecipitation techniques, the purified protein was found to associate with the chloroplast DNA polymerase. The chloroplast DNA polymerase also binds directly to the radioiodinated 43 kDa protein. The specific interaction between 43 kDa protein and chloroplast DNA polymerase results in the synthesis of longer DNA chains. The 43 kDa protein, present abundantly in the pea chloroplast, appears to increase processivity of the chloroplast DNA polymerase and may play an important role in the replication of pea chloroplast DNA.
...
PMID:A 43 kDa DNA binding protein from the pea chloroplast interacts with and stimulates the cognate DNA polymerase. 891 97

Elevated serum IgA to antigens of EBV is associated with nasopharyngeal carcinoma (NPC). We have tested 620 NPC sera by ELISA for the presence of antibodies to EBV-encoded DNA binding protein, EBV-specific DNA polymerase, early antigen-diffused (EA-D), EBV nuclear antigen 1 (EBNA-1), EBV-specific thymidine kinase, and BamHI Z fragment EBV replication antigen. Sensitivity of these proteins was in the range of 51.5-79.5% for IgA and 69.4-82.8% for IgG. The complementary use of EBNA-1 with EA-D, however, could increase the sensitivity significantly to 98.1%. Western blot analysis further showed that the combination of EBNA-1 and EA-D is most useful for the detection of NPC. This is the first report of using double biomarkers including EBV gene products from both latent and active infections. The results of this study suggest that EBV in NPC may not be latent alone and that the method may be valuable for the early detection, early treatment, and better survival rate of patients with NPC. Because the application of recombinant EBV protein in ELISA is cost-effective and feasible for mass screening, the method may be of worth for further clinical investigation.
...
PMID:Serum responses to the combination of Epstein-Barr virus antigens from both latent and acute phases in nasopharyngeal carcinoma: complementary test of EBNA-1 with EA-D. 914 97

Five serological tests were assessed for their sensitivity for screening and early detection of nasopharyngeal carcinoma (NPC). The tests included the detection of antibodies to various gene products of EBV: viral capsid antigen (VCA) using an indirect immunofluorescence assay (FA), DNase using an activity neutralisation test (NT), Dnase using an enzyme-linked immunosorbent assay (ELISA), DNA polymerase (DP) using NT, and major DNA binding protein (MDBP) by ELISA. Sera from 100 NPC outpatients and 20 NPC patients, who were detected in a prospective study, were examined. The results showed that levels of antibody to DNase detected by ELISA and to DP detected by NT and the positivity rate for VCA by FA increased with NPC stage. More species of EBV antibody became detectable as NPC progressed. The detection of anti-MDBP antibody by ELISA was suitable for screening for NPC. Anti-DP antibody detected by NT was a valuable marker both for early detection and prognosis of NPC. Detection of anti-DNase antibody by ELISA was the most sensitive method for detection of NPC. No single test was sufficient to detect all the NPC patients and a combination of anti-DNase by ELISA with other tests are recommended to identify NPC patients.
...
PMID:Evaluation of multiple antibodies to Epstein-Barr virus as markers for detecting patients with nasopharyngeal carcinoma. 921 34

A major 135-kDa DNA binding protein (mDBP) encoded by the BALF2 open reading frame of Epstein-Barr Virus (EBV) is known to be an essential protein for the induction of the lytic cycle. The present investigation was carried out to know whether this protein forms a complex in vivo with other viral DNA binding proteins (DBP) involved in DNA replication: DNA polymerase, EA-D (diffused early antigen), and DNAase. Immunoprecipitation assays followed by mono- and two-dimensional electrophoresis showed that mDBP forms a complex with these three DBP. Other complexes were also found such as EA-D/DNAase, DNA polymerase/DNAase, and DNA polymerase/EA-D. The complexed forms already exist in the early stage of EBV cycle before DNA synthesis is induced in the EBV producer P3HR-1 cell line. The exonuclease activity encoded by DNAase was found to be inhibited when this enzyme complexed with mDBP, while the EBV DNA polymerase retained its activity in the complexed form with mDBP. Our results suggest that these complexes already present before DNA synthesis are necessary for EBV DNA synthesis.
...
PMID:A major DNA binding protein encoded by BALF2 open reading frame of Epstein-Barr virus (EBV) forms a complex with other EBV DNA-binding proteins: DNAase, EA-D, and DNA polymerase. 943 20

Surface plasmon resonance measurements were used for detecting and quantifying protein-protein interactions between the tumor suppressor protein p53, the SV40 large T antigen (T-ag), the cellular DNA polymerase alpha-primase complex (pol-prim), and the cellular single-strand DNA binding protein RPA. Highly purified p53 protein bound to immobilized T-ag with an apparent binding constant of 2 x 10(8) M(-1). Binding of p53 to RPA was in the same order of magnitude with a binding constant of 4 x 10(8) M(-1), when RPA was coupled to the sensor chip via its smallest subunit, and 1 x 10(8) M(-1), when RPA was coupled via its p70 subunit. Furthermore, p53 bound human DNA polymerase alpha-primase complex (pol-prim) with a K(A) value of 1 x 10(10) m(-1). Both the p68 subunit and the p180 subunit of pol-prim could interact with p53 displaying binding constants of 2 x 10(10) m1(-1) and 5 X 10(9) M(-1), respectively. Complex formation was also observed with a p180/p68 heterodimer, and again with a binding constant similar. Hence, there was no synergistic effect when p53 bound to higher order complexes of pol-prim. A truncated form of p53, consisting of amino acids 1-320, bound pol-prim by four orders of magnitude less efficiently. Therefore, an intact C-terminus of p53 seems to be important for efficient binding to pol-prim. It was also tried to measure complex formation between p53, pol-prim, and T-ag. However there was no evidence for the existence of a ternary complex consisting of T-ag, pol-prim, and p53.
...
PMID:Surface plasmon resonance measurements reveal stable complex formation between p53 and DNA polymerase alpha. 998 27


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>

---