Mutator and Antimutator Effects of the Bacteriophage P1 hot Gene Product

ABSTRACT The Hot (homolog of theta) protein of bacteriophage P1 can substitute for the Escherichia coli DNA polymerase III θ subunit, as evidenced by its stabilizing effect on certain dnaQ mutants that carry an unstable polymerase III ε proofreading subunit (antimutator effect). Here, we show that Hot can also cause an increase in the mutability of various E. coli strains (mutator effect). The hot mutator effect differs from the one caused by the lack of θ. Experiments using chimeric θ/Hot proteins containing various domains of Hot and θ along with a series of point mutants show that both N- and C-terminal parts of each protein are important for stabilizing the ε subunit. In contrast, the N-terminal part of Hot appears uniquely responsible for its mutator activity.

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The bacteriophage P1 hot gene, encoding a homolog of the E. coli DNA polymerase III θ subunit, is expressed during both lysogenic and lytic growth stages

Mutation Research/Fundamental and Molecular Mechanisms of Mutagenesis ◽

10.1016/j.mrfmmm.2007.01.014 ◽

2007 ◽

Vol 624 (1-2) ◽

pp. 1-8 ◽

Cited By ~ 5

Author(s):

Anna K. Chikova ◽

Roel M. Schaaper

Keyword(s):

Dna Polymerase ◽

Growth Stages ◽

Dna Polymerase Iii ◽

Gene Encoding ◽

Bacteriophage P1 ◽

E Coli ◽

Polymerase Iii

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Phage Like It HOTSolution Structure of the Bacteriophage P1-Encoded HOT Protein, a Homolog of the θ Subunit of E. coli DNA Polymerase III

Structure ◽

10.1016/s0969-2126(04)00354-5 ◽

2004 ◽

Vol 12 (12) ◽

pp. 2221-2231 ◽

Cited By ~ 2

Author(s):

E DEROSE ◽

T KIRBY ◽

G MUELLER ◽

A CHIKOVA ◽

R SCHAAPER ◽

...

Keyword(s):

Dna Polymerase ◽

Protein A ◽

Dna Polymerase Iii ◽

Bacteriophage P1 ◽

E Coli ◽

Polymerase Iii

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Faculty Opinions recommendation of Mechanism of processivity clamp opening by the delta subunit wrench of the clamp loader complex of E. coli DNA polymerase III.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1001104.10052 ◽

2001 ◽

Author(s):

Janet Lindsley

Keyword(s):

Dna Polymerase ◽

Dna Polymerase Iii ◽

Clamp Loader ◽

E Coli ◽

Polymerase Iii ◽

Delta Subunit

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E. coli primase and DNA polymerase III holoenzyme are able to bind concurrently to a primed template during DNA replication

Scientific Reports ◽

10.1038/s41598-019-51031-0 ◽

2019 ◽

Vol 9 (1) ◽

Author(s):

Andrea Bogutzki ◽

Natalie Naue ◽

Lidia Litz ◽

Andreas Pich ◽

Ute Curth

Keyword(s):

Dna Replication ◽

Dna Polymerase ◽

Protein Interactions ◽

Dna Polymerase Iii ◽

Protein Protein Interactions ◽

Single Stranded Dna ◽

E Coli ◽

Polymerase Iii ◽

C Terminus ◽

Pol Iii

Abstract During DNA replication in E. coli, a switch between DnaG primase and DNA polymerase III holoenzyme (pol III) activities has to occur every time when the synthesis of a new Okazaki fragment starts. As both primase and the χ subunit of pol III interact with the highly conserved C-terminus of single-stranded DNA-binding protein (SSB), it had been proposed that the binding of both proteins to SSB is mutually exclusive. Using a replication system containing the origin of replication of the single-stranded DNA phage G4 (G4ori) saturated with SSB, we tested whether DnaG and pol III can bind concurrently to the primed template. We found that the addition of pol III does not lead to a displacement of primase, but to the formation of higher complexes. Even pol III-mediated primer elongation by one or several DNA nucleotides does not result in the dissociation of DnaG. About 10 nucleotides have to be added in order to displace one of the two primase molecules bound to SSB-saturated G4ori. The concurrent binding of primase and pol III is highly plausible, since even the SSB tetramer situated directly next to the 3′-terminus of the primer provides four C-termini for protein-protein interactions.

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The Mechanism of Replication of Single-Stranded DNA. VI. Requirements for Ribonucleoside Triphosphates and DNA Polymerase III

Canadian Journal of Biochemistry ◽

10.1139/o73-214 ◽

1973 ◽

Vol 51 (12) ◽

pp. 1588-1597 ◽

Cited By ~ 7

Author(s):

David T. Denhardt ◽

Makoto Iwaya ◽

Grant McFadden ◽

Gerald Schochetman

Keyword(s):

Dna Polymerase ◽

Dna Polymerases ◽

Temperature Sensitive ◽

Restrictive Temperature ◽

Dna Polymerase Iii ◽

Single Stranded Dna ◽

E Coli ◽

Polymerase Iii

Evidence is presented that in Escherichia coli made permeable to nucleotides by exposure to toluene, the synthesis of a DNA chain complementary to the infecting single-stranded DNA of bacteriophage [Formula: see text] requires ATP as well as the four deoxyribonucleoside triphosphates. This synthesis results in the formation of the parental double-stranded replicative-form (RF) molecule. The ATP is not required simply to prevent degradation of the ribonucleoside or deoxyribonucleoside triphosphates; it can be partially substituted for by other ribonucleoside triphosphates.No single one of the known E. coli DNA polymerases appears to be uniquely responsible in vivo for the formation of the parental RF. Since [Formula: see text] replicates well in strains lacking all, or almost all, of the in-vitro activities of DNA polymerases I and II, neither of these two enzymes would seem essential; and in a temperature-sensitive E. coli mutant (dnaEts) deficient in DNA polmerase-I activity and possessing a temperature-sensitive DNA polymerase III, the viral single-stranded DNA is efficiently incorporated into an RF molecule at the restrictive temperature. In contrast, both RF replication and progeny single-stranded DNA synthesis are dependent upon DNA polymerase III activity.

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