Roles of E. coli DNA polymerases IV and V in lesion-targeted and untargeted SOS mutagenesis

Nature ◽  
2000 ◽  
Vol 404 (6781) ◽  
pp. 1014-1018 ◽  
Author(s):  
Mengjia Tang ◽  
Phuong Pham ◽  
Xuan Shen ◽  
John-Stephen Taylor ◽  
Mike O'Donnell ◽  
...  

1973 ◽  
Vol 51 (12) ◽  
pp. 1588-1597 ◽  
Author(s):  
David T. Denhardt ◽  
Makoto Iwaya ◽  
Grant McFadden ◽  
Gerald Schochetman

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.



Genetics ◽  
1998 ◽  
Vol 148 (4) ◽  
pp. 1599-1610 ◽  
Author(s):  
Bradley T Smith ◽  
Graham C Walker

Abstract The cellular response to DNA damage that has been most extensively studied is the SOS response of Escherichia coli. Analyses of the SOS response have led to new insights into the transcriptional and posttranslational regulation of processes that increase cell survival after DNA damage as well as insights into DNA-damage-induced mutagenesis, i.e., SOS mutagenesis. SOS mutagenesis requires the recA and umuDC gene products and has as its mechanistic basis the alteration of DNA polymerase III such that it becomes capable of replicating DNA containing miscoding and noncoding lesions. Ongoing investigations of the mechanisms underlying SOS mutagenesis, as well as recent observations suggesting that the umuDC operon may have a role in the regulation of the E. coli cell cycle after DNA damage has occurred, are discussed.





1992 ◽  
Vol 3 (4) ◽  
pp. 243-247 ◽  
Author(s):  
P. J. Aduma ◽  
S. V. Gupta ◽  
A. L. Stuart

5-Methoxymethyl-2′-deoxyuridine (MMdUrd) is a selective anti-herpes agent that is dependent upon initial phosphorylation by Herpes simplex virus-induced deoxythymidine kinase. In order to determine its mechanism of action, MMdUrd was converted to the 5′-triphosphate (MMdUTP) and the nature of interaction of MMdUTP and dTTP with DNA polymerase of E. coli, HSV-1, and human α was investigated. The order of utilization of deoxyuridine analogues by bacterial and HSV-1 DNA polymerases for DNA synthesis was: dTTP > MMdUTP. In contrast, 5-methoxymethyl-2′-deoxycytidine-5′-triphosphate (MMdCTP) was a better substrate for HSV DNA polymerase compared to dCTP. MMdUTP is a competitive inhibitor of HSV-1 DNA polymerase with respect to dTTP incorporation (Ki = 2.9 × 10−6M). The IC50 values of MMdUTP for both HSV and human αDNA polymerases were 4.5 × 10 −6M. These data suggest that the selective activity of MMdUrd is due to its preferential phosphorylation by viral thymidine kinase and not at the DNA polymerase level. These results may also account for the difference in anti-HSV activity between MMdUrd and its deoxycytidine analogue.



2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Razieh Pourahmad Jaktaji ◽  
Sayedeh Marzieh Nourbakhsh Rezaei

Background: Ciprofloxacin induces SOS response and mutagenesis by activation of UmuD’2C (DNA polymerase V) and DinB (DNA polymerase IV) in Escherichia coli, leading to antibiotic resistance during therapy. Inactivation of DNA polymerase V can result in the inhibition of mutagenesis in E. coli. Objectives: The aim of this research was to investigate the effect of UmuC inactivation on resistance to ciprofloxacin and SOS mutagenesis in E. coli mutants. Methods: Ciprofloxacin-resistant mutants were produced in a umuC- genetic background in the presence of increasing concentrations of ciprofloxacin. The minimum inhibitory concentration of umuC-mutants was measured by broth dilution method. Alterations in the rifampin resistance-determing region of rpoB gene were assessed by PCR amplification and DNA sequencing. The expression of SOS genes was measured by quantitative real-time PCR assay. Results: Results showed that despite the induction of SOS response (overexpression of recA, dinB, and umuD genes) following exposure to ciprofloxacin in E. coliumuC mutants, resistance to ciprofloxacin and SOS mutagenesis significantly decreased. However, rifampicin-resistant clones emerged in this genetic background. One of these clones showed mutations in the rifampicin resistance-determining region of rpoB (cluster II). The low mutation frequency of E. coli might be associated with the presence and overexpression of umuD gene, which could somehow limit the activity of DinB, the location and type of mutations in the β subunit of RNA polymerase. Conclusions: In conclusion, for increasing the efficiency of ciprofloxacin against Gram-negative bacteria, use of an inhibitor of umuC, along with ciprofloxacin, would be helpful.



2020 ◽  
Vol 295 (26) ◽  
pp. 8775-8783
Author(s):  
Jiabin Wu ◽  
Jun Yuan ◽  
Nathan E. Price ◽  
Yinsheng Wang

Alkyl phosphotriester (alkyl-PTE) lesions are frequently induced in DNA and are resistant to repair. Here, we synthesized and characterized methyl (Me)- and n-butyl (nBu)-PTEs in two diastereomeric configurations (Sp and Rp) at six different flanking dinucleotide sites, i.e. XT and TX (X = A, C, or G), and assessed how these lesions impact DNA replication in Escherichia coli cells. When single-stranded vectors contained an Sp-Me-PTE in the sequence contexts of 5′-AT-3′, 5′-CT-3′, or 5′-GT-3′, DNA replication was highly efficient and the replication products for all three sequence contexts contained 85–90% AT and 5–10% TG. Thus, the replication outcome was largely independent of the identity of the 5′ nucleotide adjacent to an Sp-Me-PTE. Furthermore, replication across these lesions was not dependent on the activities of DNA polymerases II, IV, or V; Ada, a protein involved in adaptive response and repair of Sp-Me-PTE in E. coli, however, was essential for the generation of the mutagenic products. Additionally, the Rp diastereomer of Me-PTEs at XT sites and both diastereomers of Me-PTEs at TX sites exhibited error-free replication bypass. Moreover, Sp-nBu-PTEs at XT sites did not strongly impede DNA replication, and other nBu-PTEs displayed moderate blockage effects, with none of them being mutagenic. Taken together, these findings provide in-depth understanding of how alkyl-PTE lesions are recognized by the DNA replication machinery in prokaryotic cells and reveal that Ada contributes to mutagenesis of Sp-Me-PTEs in E. coli.



DNA Repair ◽  
2006 ◽  
Vol 5 (4) ◽  
pp. 515-522 ◽  
Author(s):  
Kwang Young Seo ◽  
Arumugam Nagalingam ◽  
Shadi Miri ◽  
Jun Yin ◽  
Sushil Chandani ◽  
...  


1977 ◽  
Vol 77 (3) ◽  
pp. 854-860 ◽  
Author(s):  
Michiko Miyaki ◽  
Ikuko Murata ◽  
Michiko Osabe ◽  
Tetsuo Ono
Keyword(s):  




2010 ◽  
Vol 2010 ◽  
pp. 1-12 ◽  
Author(s):  
Jaylene N. Ollivierre ◽  
Jing Fang ◽  
Penny J. Beuning

All organisms are subject to DNA damage from both endogenous and environmental sources. DNA damage that is not fully repaired can lead to mutations. Mutagenesis is now understood to be an active process, in part facilitated by lower-fidelity DNA polymerases that replicate DNA in an error-prone manner. Y-family DNA polymerases, found throughout all domains of life, are characterized by their lower fidelity on undamaged DNA and their specialized ability to copy damaged DNA. TwoE. coliY-family DNA polymerases are responsible for copying damaged DNA as well as for mutagenesis. These DNA polymerases interact with different forms of UmuD, a dynamic protein that regulates mutagenesis. The UmuD gene products, regulated by the SOS response, exist in two principal forms:UmuD2, which prevents mutagenesis, andUmuD2′, which facilitates UV-induced mutagenesis. This paper focuses on the multiple conformations of the UmuD gene products and how their protein interactions regulate mutagenesis.



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