Template-Free Primer-Independent DNA Synthesis by Bacterial DNA Polymerases I Using the DnaB Protein from Escherichia coli

2004 ◽  
Vol 398 (1-6) ◽  
pp. 265-267 ◽  
Author(s):  
O. K. Kaboev ◽  
L. A. Luchkina
Keyword(s):  
Escherichia Coli ◽  
Dna Synthesis ◽  
Dna Polymerases ◽  
Bacterial Dna ◽  
Template Free

Development of T7 phage and T7 phage containing apurinic sites in an exonuclease III, endonuclease IV double mutant of Escherichia coli

1992 ◽  
Vol 70 (7) ◽  
pp. 605-608 ◽  
Author(s):  
Giselle Sanchez ◽  
Margaret D. Mamet-Bratley
Keyword(s):  
Escherichia Coli ◽  
Dna Repair ◽  
Dna Synthesis ◽  
Double Mutant ◽  
Bacteriophage T7 ◽  
Bacterial Dna ◽  
Exonuclease Iii ◽  
Repair Enzymes ◽  
Phage Dna ◽  
T7 Phage

The development of bacteriophage T7 was examined in an Escherichia coli double mutant defective for the two major apurinic, apyrimidinic endonucleases (exonuclease III and endonuclease IV, xth nfo). In cells infected with phages containing apurinic sites, the defect in repair enzymes led to a decrease of phage survival and a total absence of bacterial DNA degradation and of phage DNA synthesis. These results directly demonstrate the toxic action of apurinic sites on bacteriophage T7 at the intracellular level and its alleviation by DNA repair. In addition, untreated T7 phage unexpectedly displayed reduced plating efficiency and decreased DNA synthesis in the xth nfo double mutant.Key words: apurinic sites, DNA repair, T7 phage.

scholarly journals Carcinogens inhibit DNA synthesis with isolated DNA polymerases from Escherichia coli

FEBS Letters ◽  
1978 ◽  
Vol 86 (1) ◽  
pp. 81-84 ◽  
Author(s):  
Verena Berthold ◽  
Heinz Walter Thielmann ◽  
Klaus Geider
Keyword(s):  
Escherichia Coli ◽  
Dna Synthesis ◽  
Dna Polymerases

scholarly journals Transcriptional Modulator NusA Interacts with Translesion DNA Polymerases in Escherichia coli

2008 ◽  
Vol 191 (2) ◽  
pp. 665-672 ◽  
Author(s):  
Susan E. Cohen ◽  
Veronica G. Godoy ◽  
Graham C. Walker
Keyword(s):  
Escherichia Coli ◽  
Rna Polymerase ◽  
Dna Synthesis ◽  
Dna Polymerase ◽  
Temperature Sensitivity ◽  
Dna Polymerases ◽  
Rna Polymerases ◽  
Translesion Dna Synthesis ◽  
Catalytic Activities ◽  
Translesion Dna

ABSTRACT NusA, a modulator of RNA polymerase, interacts with the DNA polymerase DinB. An increased level of expression of dinB or umuDC suppresses the temperature sensitivity of the nusA11 strain, requiring the catalytic activities of these proteins. We propose that NusA recruits translesion DNA synthesis (TLS) polymerases to RNA polymerases stalled at gaps, coupling TLS to transcription.

scholarly journals Analysis of DNA Polymerases II and III in Mutants of Escherichia coli Thermosensitive for DNA Synthesis

1971 ◽  
Vol 68 (12) ◽  
pp. 3150-3153 ◽  
Author(s):  
M. L. Gefter ◽  
Y. Hirota ◽  
T. Kornberg ◽  
J. A. Wechsler ◽  
C. Barnoux
Keyword(s):  
Escherichia Coli ◽  
Dna Synthesis ◽  
Dna Polymerases

scholarly journals CRISPR-Associated Primase-Polymerases are implicated in prokaryotic CRISPR-Cas adaptation

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Katerina Zabrady ◽  
Matej Zabrady ◽  
Peter Kolesar ◽  
Arthur W. H. Li ◽  
Aidan J. Doherty
Keyword(s):  
Dna Repair ◽  
Dna Synthesis ◽  
Genome Stability ◽  
Dna Polymerases ◽  
Acquired Immunity ◽  
Strand Displacement ◽  
Genetic Studies ◽  
Type Iiia ◽  
Maintain Genome Stability ◽  
Cas Proteins

AbstractCRISPR-Cas pathways provide prokaryotes with acquired “immunity” against foreign genetic elements, including phages and plasmids. Although many of the proteins associated with CRISPR-Cas mechanisms are characterized, some requisite enzymes remain elusive. Genetic studies have implicated host DNA polymerases in some CRISPR-Cas systems but CRISPR-specific replicases have not yet been discovered. We have identified and characterised a family of CRISPR-Associated Primase-Polymerases (CAPPs) in a range of prokaryotes that are operonically associated with Cas1 and Cas2. CAPPs belong to the Primase-Polymerase (Prim-Pol) superfamily of replicases that operate in various DNA repair and replication pathways that maintain genome stability. Here, we characterise the DNA synthesis activities of bacterial CAPP homologues from Type IIIA and IIIB CRISPR-Cas systems and establish that they possess a range of replicase activities including DNA priming, polymerisation and strand-displacement. We demonstrate that CAPPs operonically-associated partners, Cas1 and Cas2, form a complex that possesses spacer integration activity. We show that CAPPs physically associate with the Cas proteins to form bespoke CRISPR-Cas complexes. Finally, we propose how CAPPs activities, in conjunction with their partners, may function to undertake key roles in CRISPR-Cas adaptation.

scholarly journals Antimutator mutations in the alpha subunit of Escherichia coli DNA polymerase III: identification of the responsible mutations and alignment with other DNA polymerases.

Genetics ◽  
1993 ◽  
Vol 134 (4) ◽  
pp. 1039-1044 ◽  
Author(s):  
I J Fijalkowska ◽  
R M Schaaper
Keyword(s):  
Escherichia Coli ◽  
Amino Acid ◽  
Dna Polymerase ◽  
Dna Polymerases ◽  
Alpha Subunit ◽  
Sequence Motifs ◽  
Dna Polymerase Iii ◽  
Conserved Sequence ◽  
Polymerase Iii ◽  
Dna Replication Errors

Abstract The dnaE gene of Escherichia coli encodes the DNA polymerase (alpha subunit) of the main replicative enzyme, DNA polymerase III holoenzyme. We have previously identified this gene as the site of a series of seven antimutator mutations that specifically decrease the level of DNA replication errors. Here we report the nucleotide sequence changes in each of the different antimutator dnaE alleles. For each a single, but different, amino acid substitution was found among the 1,160 amino acids of the protein. The observed substitutions are generally nonconservative. All affected residues are located in the central one-third of the protein. Some insight into the function of the regions of polymerase III containing the affected residues was obtained by amino acid alignment with other DNA polymerases. We followed the principles developed in 1990 by M. Delarue et al. who have identified in DNA polymerases from a large number of prokaryotic and eukaryotic sources three highly conserved sequence motifs, which are suggested to contain components of the polymerase active site. We succeeded in finding these three conserved motifs in polymerase III as well. However, none of the amino acid substitutions responsible for the antimutator phenotype occurred at these sites. This and other observations suggest that the effect of these mutations may be exerted indirectly through effects on polymerase conformation and/or DNA/polymerase interactions.

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