Disease relevance of T7p29

• Here we present a 2.2 A crystal structure of the replicative DNA polymerase from bacteriophage T7 complexed with a primer-template and a nucleoside triphosphate in the polymerase active site [1].
• The 31-kilodalton domain is composed of fingers, palm, and thumb subdomains arranged to form a DNA binding channel reminiscent of the polymerase domains of the Klenow fragment of Escherichia coli DNA polymerase I, HIV-1 reverse transcriptase, and bacteriophage T7 RNA polymerase [2].
• In accord with these roles, T7 DNA polymerase is highly processive while E. coli DNA polymerase I has low processivity [3].
• Bacteriophage T7 DNA polymerase efficiently incorporates a chain-terminating dideoxynucleotide into DNA, in contrast to the DNA polymerases from Escherichia coli and Thermus aquaticus [4].
• T7 phage DNA polymerase is a tight 1:1 complex of the gene 5 protein (g5p) (80 kDa) of phage T7 and thioredoxin (12 kDa) from the Escherichia coli host [5].

High impact information on T7p29

• First, the clone-encoded protein is immunologically related to DNA polymerase I. Second, cells containing the gene cloned in the high copy number plasmid YEp24 overproduce the polymerase activity 4- to 5-fold as measured in yeast extracts [6].
• The DNA polymerase from phage phi29 is a B family polymerase that initiates replication using a protein as a primer, attaching the first nucleotide of the phage genome to the hydroxyl of a specific serine of the priming protein [7].
• The replisome consisting of bacteriophage T7 DNA polymerase, helicase, primase, and single-stranded DNA-binding protein mediates coordinated replication [8].
• Structural basis for the dual coding potential of 8-oxoguanosine by a high-fidelity DNA polymerase [9].
• Mutations of the corresponding tyrosine in DNA polymerase (DNAP) I increase miscoding, though effects on dNTP/rNTP discrimination for the DNAP I mutations have not been reported [10].

Chemical compound and disease context of T7p29

• Effect of manganese ions on the incorporation of dideoxynucleotides by bacteriophage T7 DNA polymerase and Escherichia coli DNA polymerase I [11].
• Kinetics of nucleotide incorporation opposite DNA bulky guanine N2 adducts by processive bacteriophage T7 DNA polymerase (exonuclease-) and HIV-1 reverse transcriptase [12].
• The DNA polymerase induced after infection of Escherichia coli by phage T7 has been purified 500-fold to near homogeneity as judged by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate [13].
• beta-L-3'-Deoxythymidine 5'-triphosphate (L-ddTTP) and beta-L-3'-deoxy-2',3'-didehydrothymidine 5'-triphosphate (L-d4TTP) were substrates for human immunodeficiency virus reverse transcriptase, Escherichia coli DNA polymerase I (Klenow), and Sequenase (modified T7 DNA polymerase) [14].
• A series of six oligonucleotides with dihydrodiol epoxide metabolites of the polycyclic aromatic hydrocarbons (PAHs) benz[a]anthracene and benzo[a]pyrene attached to adenine N6 and guanine N2 atoms were prepared and studied with the processive bacteriophage DNA polymerase T7, exonuclease- (T7-) [15].

Biological context of T7p29

• A unique loop in T7 DNA polymerase mediates the binding of helicase-primase, DNA binding protein, and processivity factor [16].
• Synthesis on single-stranded DNA by T7 DNA polymerase (DNA nucleotidyltransferase; deoxynucleosidetriphosphate:DNA deoxynucleotidyltransferase, EC 2.7.7.7) does not affect the hydrolysis of NTPs by the gene 4 protein [17].
• Error-prone replication of repeated DNA sequences by T7 DNA polymerase in the absence of its processivity subunit [18].
• Crystal structures of 2-acetylaminofluorene and 2-aminofluorene in complex with T7 DNA polymerase reveal mechanisms of mutagenesis [19].
• Bacteriophage T7 DNA polymerase shares extensive sequence homology with Escherichia coli DNA polymerase I. However, in vivo, E. coli DNA polymerase I is involved primarily in the repair of DNA whereas T7 DNA polymerase is responsible for the replication of the viral genome [3].

Anatomical context of T7p29

• E. coli Trx-(SH)2 is essential for phage T7 DNA replication as a subunit of T7 DNA polymerase and also for assembly of the filamentous phages f1 and M13 perhaps through its localization at the cellular plasma membrane [20].
• We have purified T7 DNA polymerase to homogeneity from T7-infected Escherichia coli B cells with a novel technique based on immunoadsorbent affinity chromatography [21].

Associations of T7p29 with chemical compounds

• The lack of discrimination against dideoxynucleoside triphosphates using T7 DNA polymerase and Mn2+ results in uniform terminations of DNA sequencing reactions, with the intensity of adjacent bands on polyacrylamide gels varying in most instances by less than 10% [11].
• The exchange can be monitored by the use of a genetically altered T7 DNA polymerase (gp5-Y526F) in which tyrosine-526 is replaced with phenylalanine [22].
• After a final phosphocellulose chromatography, T7 DNA polymerase of better than 99% purity, as estimated from sodium dodecyl sulfate polyacrylamide gel electrophoresis, is obtained [21].
• Results with a mutant T7 DNA polymerase in which aliphatic residues are substituted for these amino acids and experiments with different length and methylphosphonate-modified primer-templates demonstrate that these interactions are essential for processive synthesis and d(A.T)(n) tract bypass [23].
• Beta-L-thymidine 5'-triphosphate analogs as DNA polymerase substrates [14].

Physical interactions of T7p29

• The phage T7 single-stranded DNA-binding protein gp2.5 specifically interfered with the utilization of tetraribonucleotide primers by interacting with T7 DNA polymerase and preventing a productive interaction with the primed template [24].

Regulatory relationships of T7p29

• The T7 gene 4 protein acts processively as helicase to promote leading strand synthesis and distributively as primase to initiate lagging strand synthesis by T7 DNA polymerase [25].

Other interactions of T7p29

• The 3' to 5' exonuclease activity of bacteriophage T7 DNA polymerase (gene 5 protein) can be inactivated selectively by reactive oxygen species [26].
• Initiation of DNA synthesis can be reconstituted using T7 RNA polymerase, T7 DNA polymerase, and T7 origin-containing plasmid DNAs [27].
• DNA synthesis catalyzed by Form II of T7 DNA polymerase eliminates gaps to create a substrate for DNA ligase whereas strand displacement synthesis catalyzed by Form I creates an aberrant structure that cannot be joined [28].
• These cleavages required the products of genes 3 (endonuclease), 4 (DNA primase), and 5 (DNA polymerase) [29].

Analytical, diagnostic and therapeutic context of T7p29

• Analysis by electron microscopy shows that T7 DNA polymerase [DNA nucleotidyltransferase (DNA-directed), EC 2.7.7.7] and gene 4 protein initiate DNA synthesis at randomly located nicks on duplex DNA to produce branched molecules [30].
• GP2.5-delta 21C does not physically interact with T7 DNA polymerase as measured by affinity chromatography and fluorescent emission anisotropy [31].
• Measurements of surface plasmon resonance indicate that a monomer of T7 DNA polymerase binds to a dimer of gp4, gp4-C219, or gp4-C241 but to a monomer of gp4-C272 [32].
• T7 DNA polymerase and gene 4 protein associate to form a complex that can be isolated by filtration through a molecular sieve [33].
• T7 DNA polymerase forms a stable complex with single-stranded M13 DNA at 50 mM NaCl as measured by gel filtration, and this complex requires 200 mM NaCl for dissociation, a salt concentration that inhibits RNA-primed DNA synthesis [33].

References