Mutations induced by Bleomycin, 4-nitroquinoline-1-oxide, and hydrogen peroxide in the rpoB gene of Escherichia coli : Perspective on Mutational Hotspots

Copyright © 2020 Elsevier B.V. All rights reserved..

We report the mutational spectra in a segment of the E. coli rpoB gene of bleomycin (BLEO), 4-nitroquinoline-1-oxide (NQO), and hydrogen peroxide (H2O2). We compare these spectra with those of other mutagens and repair deficient strains in the same rpoB system, and review the key elements determining mutational hotspots and outline the questions that remain unanswered. We consider three tiers of hotspots that derive from 1) the nature of the sequence change at a specific base, 2) the direct nearest neighbors and 3) some aspect of the larger sequence context or the local 3D-structure of segments of DNA. This latter tier can have a profound effect on mutation frequencies, even among sites with identical nearest neighbor sequences. BLEO is dependent on the SOS-induced translesion Pol V for mutagenesis, and has a dramatic hotspot at a single mutational site in rpoB. NQO is not dependent on any of the translesion polymerases, in contrast to findings with plasmids treated in vitro and transformed into E. coli. The rpoB system allows one to monitor both G:C -> A:T transitions and G:C -> T:A transversions at the same site in 11 cases, each site having the identical sequence context for each of the two mutations. The combined preference for G:C -> A:T transitions at these sites is 20-fold. Several of the favored sites for hydrogen peroxide mutagenesis are not seen in the spectra of BLEO and NQO mutations, indicating that mutagenesis from reactive oxygen species is not a major cause of BLEO or NQO mutagenesis, but rather specific adducts. The variance in mutation rates at sites with identical nearest neighbors suggests that the local structure of different DNA segments is an important factor in mutational hotspots.

Medienart:

E-Artikel

Erscheinungsjahr:

2020

Erschienen:

2020

Enthalten in:

Zur Gesamtaufnahme - volume:821

Enthalten in:

Mutation research - 821(2020) vom: 01. Mai, Seite 111702

Sprache:

Englisch

Beteiligte Personen:

Fernandez, Kristen [VerfasserIn]
D'Souza, Sara [VerfasserIn]
Ahn, Jenny J [VerfasserIn]
Singh, Summer [VerfasserIn]
Bacasen, Erin Mae [VerfasserIn]
Mashiach, Daniel [VerfasserIn]
Mishail, Daniel [VerfasserIn]
Kao, Timothy [VerfasserIn]
Thai, Jasmine [VerfasserIn]
Hwang, Spring [VerfasserIn]
Yaramada, Lekha [VerfasserIn]
Miller, Jeffrey H [VerfasserIn]

Links:

Volltext

Themen:

11056-06-7
4-Nitroquinoline-1-oxide
4-nitroquinoline-1-oxide
56-57-5
Antibiotics, Antineoplastic
BBX060AN9V
Bleomycin
DNA-Directed RNA Polymerases
EC 2.7.7.6
Escherichia coli Proteins
Hotspots
Hydrogen Peroxide
Journal Article
Mutagens
Mutation
Oxidants
Research Support, Non-U.S. Gov't
RpoB protein, E coli
RpoBsystem

Anmerkungen:

Date Completed 08.12.2020

Date Revised 14.12.2020

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1016/j.mrfmmm.2020.111702

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM31005074X