Counteraction by MutT protein of transcriptional errors caused by oxidative damage.
Oxidized guanine (8-oxo-7,8-dihydroguanine; 8-oxo-G) is a potent mutagen because of its ambiguous pairing with cytosine and adenine. The Escherichia coli MutT protein specifically hydrolyzes both 8-oxo-deoxyguanosine triphosphate (8-oxo-dGTP) and 8-oxo-guanosine triphosphate (8-oxo-rGTP), which are otherwise incorporated in DNA and RNA opposite template A. In vivo, this cleaning of the nucleotide pools decreases both DNA replication and transcription errors. The effect of mutT mutation on transcription fidelity was shown to depend on oxidative metabolism. Such control of transcriptional fidelity by the ubiquitous MutT function has implications for evolution of RNA-based life, phenotypic expression, adaptive mutagenesis, and functional maintenance of nondividing cells.
Taddei
F
F
Institut Jacques Monod, Tour 43, 2 place Jussieu, 75251 Paris Cedex 05, France. taddei@ijm.jussieu.fr
Hayakawa
H
H
Bouton
M
M
Cirinesi
A
A
Matic
I
I
Sekiguchi
M
M
Radman
M
M
D000332:Aerobiosis; D000693:Anaerobiosis; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D003062:Codon; D003848:Deoxyguanine Nucleotides / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D029968:Escherichia coli Proteins; D006160:Guanosine Triphosphate / Q000031:analogs & derivatives* / Q000378:metabolism; D006868:Hydrolysis; D007763:Lac Operon; D009154:Mutation; D010084:Oxidation-Reduction; D010744:Phosphoric Monoester Hydrolases / Q000235:genetics / Q000378:metabolism*; D017354:Point Mutation; D011755:Pyrophosphatases; D012329:RNA, Bacterial / Q000096:biosynthesis / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis* / Q000235:genetics; D013698:Templates, Genetic; D014158:Transcription, Genetic; D014161:Transduction, Genetic; D001616:beta-Galactosidase / Q000378:metabolism
D001426:Bacterial Proteins; D003062:Codon; D003848:Deoxyguanine Nucleotides; D029968:Escherichia coli Proteins; D012329:RNA, Bacterial; D012333:RNA, Messenger; C078206:8-oxodeoxyguanosine triphosphate; C057674:8-hydroxyguanosine triphosphate; D006160:Guanosine Triphosphate; D010744:Phosphoric Monoester Hydrolases; D001616:beta-Galactosidase; D011755:Pyrophosphatases; C052211:mutT protein, E coli