Removal of 8-oxo-GTP by MutT hydrolase is not a major contributor to transcriptional fidelity
Year: 2014
Type: article
Abstract: Living in an oxygen-rich environment is dangerous for a cell. Reactive oxygen species can damage DNA, RNA, protein and lipids. The MutT protein in Escherichia coli removes 8-oxo-deoxyguanosine triphosphate (8-oxo-dGTP) and 8-oxo-guanosine triphosphate (8-oxo-GTP) from the nucleotide pools precluding incorporation into DNA and RNA. While 8-oxo-dGTP incorporation into DNA is mutagenic, it is not clear if 8-oxo-GTP incorporation into RNA can have phenotypic consequences for the cell. We use a bistable epigenetic switch sensitive to transcription errors in the Escherichia coli lacI transcript to monitor transient RNA errors. We do not observe any increase in epigenetic switching in mutT cells. We revisit the original observation of partial phenotypic suppression of a lacZamber allele in a mutT background that was attributed to RNA errors. We find that Lac+ revertants can completely account for the increase in β-galactosidase levels in mutT lacZamber cultures, without invoking participation of transient transcription errors. Moreover, we observe a fluctuation type of distribution of β-galactosidase appearance in a growing culture, consistent with Lac+ DNA revertant events. We conclude that the absence of MutT produces a DNA mutator but does not equally create an RNA mutator.
Source: Nucleic Acids Research
DOI: 10.1093/nar/gku912
Language: English
Topic: DNA Repair Mechanisms
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: gold
Estimated APC paid: $3,992
Awards: G1271312710, Baylor-UT Houston Center for AIDS Research, G1793308862, BD Biosciences Special Order LSRII, G306787497, G3405376813, G3783386658, G3806108723, G4094006245, G4633610876, G4638824329, G5248451359, G5465708471, GENE REGULATION IN PHAGE LAMBDA: A REAL-TIME STUDY WITH SINGLE-EVENT RESOLUTION, CAREER: Towards a quantitative picture of gene regulation in individual cells, G6113482217, G6671297155, Cause and Consequence of Transcription Errors in Biological Networks, G9000021417, G9000032296, G9000061739, G9000198215, G9000240210, Baylor College of Medicine Cancer Center - Cancer Center Support Grant
OpenAlex ID: W2106708096