scholarly journals Mutator Phenotype Resulting from DNA Polymerase IV Overproduction in Escherichia coli: Preferential Mutagenesis on the Lagging Strand

2005 ◽  
Vol 187 (19) ◽  
pp. 6862-6866 ◽  
Author(s):  
Wojciech Kuban ◽  
Magdalena Banach-Orlowska ◽  
Malgorzata Bialoskorska ◽  
Aleksandra Lipowska ◽  
Roel M. Schaaper ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Dna Polymerase ◽  
Mutator Phenotype ◽  
Polymerase Iii ◽  
Mutator Activity ◽  
Mutator Effect ◽  
Dna Polymerase Iv ◽  
Lagging Strand

ABSTRACT We investigated the mutator effect resulting from overproduction of Escherichia coli DNA polymerase IV. Using lac mutational targets in the two possible orientations on the chromosome, we observed preferential mutagenesis during lagging strand synthesis. The mutator activity likely results from extension of mismatches produced by polymerase III holoenzyme.

scholarly journals Examination of the Role of DNA Polymerase Proofreading in the Mutator Effect of Miscoding tRNAs

1998 ◽  
Vol 180 (21) ◽  
pp. 5712-5717 ◽  
Author(s):  
Malgorzata M. Slupska ◽  
Angela G. King ◽  
Louise I. Lu ◽  
Rose H. Lin ◽  
Emily F. Mao ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Aspartic Acid ◽  
Dna Polymerase ◽  
Mutation Rate ◽  
Mutator Phenotype ◽  
Polymerase Iii ◽  
In Series ◽  
Mutator Effect

ABSTRACT We previously described Escherichia coli mutator tRNAs that insert glycine in place of aspartic acid and postulated that the elevated mutation rate results from generating a mutator polymerase. We suggested that the proofreading subunit of polymerase III, ɛ, is a likely target for the aspartic acid-to-glycine change that leads to a lowered fidelity of replication, since the altered ɛ subunits resulting from this substitution (approximately 1% of the time) are sufficient to create a mutator effect, based on several observations of mutDalleles. In the present work, we extended the study of specificmutD alleles and constructed 16 altered mutDgenes by replacing each aspartic acid codon, in series, with a glycine codon in the dnaQ gene that encodes ɛ. We show that three of these genes confer a strong mutator effect. We have also looked for new mutator tRNAs and have found one: a glycine tRNA that inserts glycine at histidine codons. We then replaced each of the seven histidine codons in the mutD gene with glycine codons and found that in two cases, a strong mutator phenotype results. These findings are consistent with the ɛ subunit playing a major role in the mutator effect of misreading tRNAs.

scholarly journals Role of DNA Polymerase IV in Escherichia coli SOS Mutator Activity

2006 ◽  
Vol 188 (22) ◽  
pp. 7977-7980 ◽  
Author(s):  
Wojciech Kuban ◽  
Magdalena Banach-Orlowska ◽  
Roel M. Schaaper ◽  
Piotr Jonczyk ◽  
Iwona J. Fijalkowska
Keyword(s):  
Escherichia Coli ◽  
Gene Product ◽  
Dna Polymerase ◽  
Constitutive Expression ◽  
Significant Fraction ◽  
Mutator Phenotype ◽  
Mutator Activity ◽  
Dna Polymerase V ◽  
Dna Polymerase Iv

ABSTRACT Constitutive expression of the SOS regulon in Escherichia coli recA730 strains leads to a mutator phenotype (SOS mutator) that is dependent on DNA polymerase V (umuDC gene product). Here we show that a significant fraction of this effect also requires DNA polymerase IV (dinB gene product).

scholarly journals Mutator and Antimutator Effects of the Bacteriophage P1 hot Gene Product

2006 ◽  
Vol 188 (16) ◽  
pp. 5831-5838 ◽  
Author(s):  
Anna K. Chikova ◽  
Roel M. Schaaper
Keyword(s):  
Dna Polymerase ◽  
Dna Polymerase Iii ◽  
Terminal Part ◽  
Bacteriophage P1 ◽  
E Coli ◽  
Polymerase Iii ◽  
Mutator Activity ◽  
Stabilizing Effect ◽  
Mutator Effect ◽  
The One

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.

scholarly journals A strategically located serine residue is critical for the mutator activity of DNA polymerase IV from Escherichia coli

2013 ◽  
Vol 41 (9) ◽  
pp. 5104-5114 ◽  
Author(s):  
Amit Sharma ◽  
Jithesh Kottur ◽  
Naveen Narayanan ◽  
Deepak T. Nair
Keyword(s):  
Escherichia Coli ◽  
Dna Polymerase ◽  
Serine Residue ◽  
Mutator Activity ◽  
Dna Polymerase Iv

scholarly journals Escherichia coli DNA Polymerase IV Mutator Activity: Genetic Requirements and Mutational Specificity

2000 ◽  
Vol 182 (16) ◽  
pp. 4587-4595 ◽  
Author(s):  
Jérôme Wagner ◽  
Takehiko Nohmi
Keyword(s):  
Escherichia Coli ◽  
Dna Polymerase ◽  
Amino Acid Level ◽  
Nucleotide Substitutions ◽  
Pol Iv ◽  
Mutator Activity ◽  
Sequence Homologies ◽  
In The Wild ◽  
Dna Polymerase Iv ◽  
Dna Pol Iv

ABSTRACT The dinB gene of Escherichia coli is known to be involved in the untargeted mutagenesis of λ phage. Recently, we have demonstrated that this damage-inducible and SOS-controlled gene encodes a novel DNA polymerase, DNA Pol IV, which is able to dramatically increase the untargeted mutagenesis of F′ plasmid. At the amino acid level, DNA Pol IV shares sequence homologies with E. coli UmuC (DNA Pol V), Rev1p, and Rad30p (DNA polymerase η) ofSaccharomyces cerevisiae and human Rad30A (XPV) proteins, all of which are involved in translesion DNA synthesis. To better characterize the Pol IV-dependent untargeted mutagenesis, i.e., the DNA Pol IV mutator activity, we analyzed the genetic requirements of this activity and determined the forward mutation spectrum generated by this protein within the cII gene of λ phage. The results indicated that the DNA Pol IV mutator activity is independent ofpolA, polB, recA,umuDC, uvrA, and mutS functions. The analysis of more than 300 independent mutations obtained in the wild-type or mutS background revealed that the mutator activity clearly promotes single-nucleotide substitutions as well as one-base deletions in the ratio of about 1:2. The base changes were strikingly biased for substitutions toward G:C base pairs, and about 70% of them occurred in 5′-GX-3′ sequences, where X represents the base (T, A, or C) that is mutated to G. These results are discussed with respect to the recently described biochemical characteristics of DNA Pol IV.

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