Roles of chromosomal and episomal dinB genes encoding DNA pol IV in targeted and untargeted mutagenesis in Escherichia coli

2001 ◽  
Vol 266 (2) ◽  
pp. 207-215 ◽  
Author(s):  
S.-R. Kim ◽  
K. Matsui ◽  
M. Yamada ◽  
P. Gruz ◽  
T. Nohmi
Keyword(s):  
Escherichia Coli ◽  
Pol Iv ◽  
Genes Encoding ◽  
Dna Pol 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.

scholarly journals Competition of Escherichia coli DNA Polymerases I, II and III with DNA Pol IV in Stressed Cells

PLoS ONE ◽  
2010 ◽  
Vol 5 (5) ◽  
pp. e10862 ◽  
Author(s):  
P. J. Hastings ◽  
Megan N. Hersh ◽  
P. C. Thornton ◽  
Natalie C. Fonville ◽  
Andrew Slack ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Dna Polymerases ◽  
Pol Iv ◽  
Stressed Cells ◽  
Dna Pol Iv

scholarly journals An Active Site Aromatic Triad in Escherichia coli DNA Pol IV Coordinates Cell Survival and Mutagenesis in Different DNA Damaging Agents

PLoS ONE ◽  
2011 ◽  
Vol 6 (5) ◽  
pp. e19944 ◽  
Author(s):  
Ryan W. Benson ◽  
Matthew D. Norton ◽  
Ida Lin ◽  
William S. Du Comb ◽  
Veronica G. Godoy
Keyword(s):  
Escherichia Coli ◽  
Cell Survival ◽  
Active Site ◽  
Pol Iv ◽  
Dna Damaging Agents ◽  
Dna Pol Iv

scholarly journals Molecular Epidemiology of NDM-1-Producing Enterobacteriaceae and Acinetobacter baumannii Isolates from Pakistan

2014 ◽  
Vol 58 (9) ◽  
pp. 5589-5593 ◽  
Author(s):  
Anna L. Sartor ◽  
Muhammad W. Raza ◽  
Shahid A. Abbasi ◽  
Kathryn M. Day ◽  
John D. Perry ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Molecular Epidemiology ◽  
Genetic Relatedness ◽  
Antibiotic Resistance Genes ◽  
Enterobacter Cloacae ◽  
Content Type ◽  
Plasmid Replicon ◽  
Genes Encoding ◽  
Clonal Spread ◽  
Encoding Genes

ABSTRACTThe molecular epidemiology of 66 NDM-producing isolates from 2 Pakistani hospitals was investigated, with their genetic relatedness determined using repetitive sequence-based PCR (Rep-PCR). PCR-based replicon typing and screening for antibiotic resistance genes encoding carbapenemases, other β-lactamases, and 16S methylases were also performed. Rep-PCR suggested a clonal spread ofEnterobacter cloacaeandEscherichia coli. A number of plasmid replicon types were identified, with the incompatibility A/C group (IncA/C) being the most common (78%). 16S methylase-encoding genes were coharbored in 81% of NDM-producingEnterobacteriaceae.

scholarly journals Shiga Toxins, and the Genes Encoding Them, in Fecal Samples from Native Idaho Ungulates

2008 ◽  
Vol 75 (3) ◽  
pp. 862-865 ◽  
Author(s):  
Jeremy J. Gilbreath ◽  
Malcolm S. Shields ◽  
Rebekah L. Smith ◽  
Larry D. Farrell ◽  
Peter P. Sheridan ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Wild Ungulates ◽  
Fecal Samples ◽  
Shiga Toxins ◽  
Toxin Genes ◽  
Genes Encoding ◽  
Shiga Toxin Genes

ABSTRACT Cattle are a known reservoir of Shiga toxin-producing Escherichia coli. The prevalence and stability of Shiga toxin and/or Shiga toxin genes among native wild ungulates in Idaho were investigated. The frequency of both Shiga genes and toxin was similar to that reported for Idaho cattle (∼19%).

Characteristics of Shiga Toxin–Producing Escherichia coli Isolated from Swiss Raw Milk Cheese within a 3-Year Monitoring Program

2010 ◽  
Vol 73 (1) ◽  
pp. 88-91 ◽  
Author(s):  
C. ZWEIFEL ◽  
N. GIEZENDANNER ◽  
S. CORTI ◽  
G. KRAUSE ◽  
L. BEUTIN ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Monitoring Program ◽  
Raw Milk ◽  
Health Impact ◽  
Toxin Gene ◽  
Genes Encoding ◽  
Raw Milk Cheese ◽  
Human Infections ◽  
Hard Cheese

Food is an important vehicle for transmission of Shiga toxin–producing Escherichia coli (STEC). To assess the potential public health impact of STEC in Swiss raw milk cheese produced from cow's, goat's, and ewe's milk, 1,422 samples from semihard or hard cheese and 80 samples from soft cheese were examined for STEC, and isolated strains were further characterized. By PCR, STEC was detected after enrichment in 5.7% of the 1,502 raw milk cheese samples collected at the producer level. STEC-positive samples comprised 76 semihard, 8 soft, and 1 hard cheese. By colony hybridization, 29 STEC strains were isolated from 24 semihard and 5 soft cheeses. Thirteen of the 24 strains typeable with O antisera belonged to the serogroups O2, O22, and O91. More than half (58.6%) of the 29 strains belonged to O:H serotypes previously isolated from humans, and STEC O22:H8, O91:H10, O91:H21, and O174:H21 have also been identified as agents of hemolytic uremic syndrome. Typing of Shiga toxin genes showed that stx1 was only found in 2 strains, whereas 27 strains carried genes encoding for the Stx2 group, mainly stx2 and stx2vh-a/b. Production of Stx2 and Stx2vh-a/b subtypes might be an indicator for a severe outcome in patients. Nine strains harbored hlyA (enterohemorrhagic E. coli hemolysin), whereas none tested positive for eae (intimin). Consequently, semihard and hard raw milk cheese may be a potential source of STEC, and a notable proportion of the isolated non-O157 STEC strains belonged to serotypes or harbored Shiga toxin gene variants associated with human infections.

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