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001-es BibID:	BIBFORM101030
035-os BibID:	(cikkazonosító)e00567-19
Első szerző:	Kapoor, Indu
Cím:	Nucleoside Diphosphate Kinase Escalates A-to-C Mutations in MutT-Deficient Strains of Escherichia coli / Kapoor Indu, Emam Elhassan Ali Fathi, Shaw Abhirup, Varshney Umesh
Dátum:	2019
ISSN:	0021-9193
Megjegyzések:	The chemical integrity of the nucleotide pool and its homeostasis are crucial for genome stability. Nucleoside diphosphate kinase (NDK) is a crucial enzyme that carries out reversible conversions from nucleoside diphosphate (NDP) to nucleoside triphosphate (NTP) and deoxynucleoside diphosphate (dNDP) to deoxy-nucleoside triphosphate (dNTP). Guanosine nucleotides (GDP, GTP, dGDP, and dGTP) are highly susceptible to oxidative damage to 8-oxo-GDP (8-O-GDP), 8-O-dGTP, 8-O-GTP, and 8-O-dGTP. MutT proteins in cells hydrolyze 8-O-GTP to 8-O-GMP or 8-O-dGTP to 8-O-dGMP to avoid its incorporation in nucleic acids. In Escherichia coli,8-O-dGTP is also known to be hydrolyzed by RibA (GTP cyclohydrolase II). In this study, we show that E. coli NDK catalyzes the conversion of 8-O-dGDP to 8-O-dGTP or vice versa. However, the rate of NDK-mediated phosphorylation of 8-O-dGDP to 8-O-dGTP is about thrice as efficient as the rate of dephosphorylation of 8-O-dGTPto 8-O-dGDP, suggesting an additive role of NDK in net production of 8-O-dGTP in cells. Consistent with this observation, the depletion of NDK (?ndk) in E. coli ?mutTor ?mutT?ribA strains results in a decrease of A-to-C mutations. These observations suggest that NDK contributes to the physiological load of MutT in E. coli.
Tárgyszavak:	Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban folyóiratcikk dNTP 8-oxo-dGTP (8-O-dGTP) MutT NDK mutation rate and mutation frequency
Megjelenés:	Journal Of Bacteriology. - 202 : 1 (2019), p. 1-10. -
További szerzők:	Emam, Elhassan Ali Fathi Shaw, Abhirup (1992-) Varshney, Umesh
Internet cím:	Szerző által megadott URL DOI Intézményi repozitóriumban (DEA) tárolt változat
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001-es BibID:	BIBFORM101029
035-os BibID:	(cikkazonosító)103316
Első szerző:	Kapoor, Indu
Cím:	Role of the nucleotide excision repair pathway proteins (UvrB and UvrD2) in recycling UdgB, a base excision repair enzyme in Mycobacterium smegmatis / Kapoor Indu, Shaw Abhirup, Naha Arindam, Emam Elhassan Ali Fathi, Varshney Umesh
Dátum:	2022
ISSN:	1568-7864
Megjegyzések:	Cross-talks between DNA repair pathways are emerging as a crucial strategy in the maintenance of the genomic integrity. A double-stranded (ds) DNA specific DNA glycosylase, UdgB is known to excise uracil, hypoxanthine and ethenocytosine. We earlier showed that Mycobacterium smegmatis (Msm) UdgB stays back on the AP-sites it generates in the DNA upon excision of the damaged bases. Here, we show that in an Msm strain deleted for a nucleotide excision repair (NER) protein, UvrB (uvrB?), UdgB expression is toxic, and its deletion from the genome (udgB?) rescues the strain from the genotoxic stress. However, UdgB bound AP-site is not a direct substrate for NER in vitro. We show that UvrD2 and UvrB, known helicases with single-stranded (ss) DNA translocase activity, facilitate recycling of UdgB from AP-DNA. Our studies reveal that the helicases play an important role in exposing the AP-sites in DNA and make them available for further repair.
Tárgyszavak:	Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban folyóiratcikk Helicases Lsr2 RNA polymerase Translocases UvrB UvrD2
Megjelenés:	Dna Repair. - 113 (2022), p. 1-14. -
További szerzők:	Shaw, Abhirup (1992-) Naha, Arindam Emam, Elhassan Ali Fathi Varshney, Umesh
Internet cím:	Szerző által megadott URL DOI Intézményi repozitóriumban (DEA) tárolt változat
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