Escherichia coli induces DNA repair enzymes to protect itself from low‐grade hydrogen peroxide stress

2021 ◽  
Author(s):  
Anshika Gupta ◽  
James A. Imlay
Keyword(s):  
Escherichia Coli ◽  
Hydrogen Peroxide ◽  
Dna Repair ◽  
Low Grade ◽  
Dna Repair Enzymes ◽  
Repair Enzymes ◽  
Peroxide Stress

scholarly journals Biochemical Characterization of Mycobacterium tuberculosis DNA Repair Enzymes – Nfo, XthA and Nei2

2014 ◽  
Vol 2 ◽  
Author(s):  
Sailau Abeldenov ◽  
Murat Saparbayev ◽  
Bekbolat Khassenov
Keyword(s):  
Escherichia Coli ◽  
Dna Repair ◽  
Mycobacterium Tuberculosis ◽  
Recombinant Proteins ◽  
Biochemical Characterization ◽  
Ion Trap ◽  
Affinity Column ◽  
Dna Repair Enzymes ◽  
Repair Enzymes

Introduction: Tuberculosis (TB) is a human disease caused by Mycobacterium tuberculosis (Mtb). Treatment of TB requires long-term courses of multi-drug therapies to eliminate subpopulations of bacteria, which sometimes persist against antibiotics. Therefore, understanding of the mechanism of Mtb antibiotic-resistance is extremely important. During infection, Mtb overcomes a variety of body defense mechanisms, including treatment with the reactive species of oxygen and nitrogen. The bases in DNA molecule are susceptible to the damages caused by reactive forms of intermediate compounds of oxygen and nitrogen. Most of this damage is repaired by the base excision repair (BER) pathway. In this study, we aimed to biochemically characterize three Mtb DNA repair enzymes of BER pathway.Methods: XthA, nfo, and nei genes were identified in mycobacteria by homology search of genomic sequences available in the GenBank database. We used standard methods of genetic engineering  to clone and sequence Mtb genes, which coded Nfo, XthA and Nei2 repair enzymes. The protein products of Mtb genes were expressed and purified in Escherichia coli using affinity tags. The enzymatic activity of purified Nfo, XthA, and Nei2 proteins were measured using radioactively labeled DNA substrates containing various modified residues. Results: The genes end (Rv0670), xthA (Rv0427c), and nei (Rv3297) were PCR amplified using genomic DNA of Mtb H37Rv with primers that contain specific restriction sites. The amplified products were inserted into pET28c(+) expression vector in such a way that the recombinant proteins contain C-terminal histidine tags. The plasmid constructs were verified by sequencing and then transformed into the Escherichia coli BL21 (DE3) strain. Purification of recombinant proteins was performed using Ni2+ ions immobilized affinity column, coupled with the fast performance liquid chromatography machine AKTA. Identification of the isolated proteins was performed by protein mass spectrometry by ion trap tandem MS/MS on nLC-ESI-Ion-Trap platform. Biochemical characterization of DNA repair protein-catalyzed activity was carried out by measuring apurinic/apyrimidinic endonuclease, DNA glycosylase, exonuclease, and 3'-repair diesterase functions. In addition, effect of the opposite base and the influence of metal ion cofactors were measured. Conclusion: Results of the ongoing study will help us define the role of DNA repair enzymes in the emergence of mutations in the mycobacterial genome and, possibly, the origins of multi-drug resistance in mycobacteria.  

scholarly journals DASH-type cryptochromes – solved and open questions

2020 ◽  
Vol 401 (12) ◽  
pp. 1487-1493
Author(s):  
Stephan Kiontke ◽  
Tanja Göbel ◽  
Annika Brych ◽  
Alfred Batschauer
Keyword(s):  
Dna Repair ◽  
Circadian Clock ◽  
Blue Light ◽  
Dna Repair Enzymes ◽  
Repair Enzymes ◽  
Open Questions ◽  
Essential Components ◽  
Repair Activity ◽  
Almost All ◽  
Uv Lesions

AbstractDrosophila, Arabidopsis, Synechocystis, human (DASH)-type cryptochromes (cry-DASHs) form one subclade of the cryptochrome/photolyase family (CPF). CPF members are flavoproteins that act as DNA-repair enzymes (DNA-photolyases), or as ultraviolet(UV)-A/blue light photoreceptors (cryptochromes). In mammals, cryptochromes are essential components of the circadian clock feed-back loop. Cry-DASHs are present in almost all major taxa and were initially considered as photoreceptors. Later studies demonstrated DNA-repair activity that was, however, restricted to UV-lesions in single-stranded DNA. Very recent studies, particularly on microbial organisms, substantiated photoreceptor functions of cry-DASHs suggesting that they could be transitions between photolyases and cryptochromes.

p21Cip1/WAF1/Sdi1Does Not Affect Expression of Base Excision DNA Repair Enzymes During Chronic Oxidative Stress

2005 ◽  
Vol 7 (5-6) ◽  
pp. 719-725 ◽  
Author(s):  
Michael A. O'Reilly ◽  
Peter F. Vitiello ◽  
Sean C. Gehen ◽  
Rhonda J. Staversky
Keyword(s):  
Oxidative Stress ◽  
Dna Repair ◽  
Dna Repair Enzymes ◽  
Repair Enzymes ◽  
Chronic Oxidative Stress ◽  
Affect Expression ◽  
Base Excision ◽  
Base Excision Dna Repair

Genotype Profiles of Loci Encoding DNA Repair Enzymes in Newborn and Elderly Populations: No Evidence of Association with Longevity

2006 ◽  
Vol 7 (1) ◽  
pp. 35-41 ◽  
Author(s):  
C. S. Wilding ◽  
G. S. Rees ◽  
C. L. Relton ◽  
E. J. Tawn
Keyword(s):  
Dna Repair ◽  
Dna Repair Enzymes ◽  
Repair Enzymes ◽  
Elderly Populations

DNA Repair Enzymes in Mammalian Cells

1977 ◽  
pp. 263-322 ◽  
Author(s):  
Errol C. Friedberg ◽  
Kern H. Cook ◽  
James Duncan ◽  
Kristien Mortelmans
Keyword(s):  
Dna Repair ◽  
Mammalian Cells ◽  
Dna Repair Enzymes ◽  
Repair Enzymes

scholarly journals DNA damage shifts circadian clock time via Hausp-dependent Cry1 stabilization

eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Stephanie J Papp ◽  
Anne-Laure Huber ◽  
Sabine D Jordan ◽  
Anna Kriebs ◽  
Madelena Nguyen ◽  
...  
Keyword(s):  
Dna Damage ◽  
Dna Repair ◽  
Circadian Clock ◽  
Transcriptional Response ◽  
Genotoxic Stress ◽  
Genomic Integrity ◽  
Clock Time ◽  
Dna Repair Enzymes ◽  
Repair Enzymes ◽  
Specific Protease

The circadian transcriptional repressors cryptochrome 1 (Cry1) and 2 (Cry2) evolved from photolyases, bacterial light-activated DNA repair enzymes. In this study, we report that while they have lost DNA repair activity, Cry1/2 adapted to protect genomic integrity by responding to DNA damage through posttranslational modification and coordinating the downstream transcriptional response. We demonstrate that genotoxic stress stimulates Cry1 phosphorylation and its deubiquitination by Herpes virus associated ubiquitin-specific protease (Hausp, a.k.a Usp7), stabilizing Cry1 and shifting circadian clock time. DNA damage also increases Cry2 interaction with Fbxl3, destabilizing Cry2. Thus, genotoxic stress increases the Cry1/Cry2 ratio, suggesting distinct functions for Cry1 and Cry2 following DNA damage. Indeed, the transcriptional response to genotoxic stress is enhanced in Cry1−/− and blunted in Cry2−/− cells. Furthermore, Cry2−/− cells accumulate damaged DNA. These results suggest that Cry1 and Cry2, which evolved from DNA repair enzymes, protect genomic integrity via coordinated transcriptional regulation.

scholarly journals Structural and cellular analyses of cancer-associated mutations in DNA repair enzymes

2019 ◽  
Vol 75 (a1) ◽  
pp. a327-a327
Author(s):  
Brian E. Eckenroth ◽  
Ash Prakash ◽  
Brittany L. Carroll ◽  
Joann B. Sweasy ◽  
Sylvie Doublié
Keyword(s):  
Dna Repair ◽  
Dna Repair Enzymes ◽  
Repair Enzymes
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