Exposure of Escherichia coli to UV light increases expression NrdAB, the major ribonucleotide reductase leading a moderate increase in dNTP levels. The role elevated levels during translesion synthesis (TLS) across specific replication-blocking lesions was investigated. Here we show that although specialized DNA polymerase PolV is necessary for replication UV-lesions, such as cyclobutane pyrimidine dimers or pyrimidine(6-4)pyrimidone photoproduct, Pol V per se not sufficient. Indeed,...

We have constructed plasmids pS3G-1 and pSG4 that contain single acetylaminofluorene adducts within contiguous runs of three (5'-CCCG1G2G3-3') four (5'-CG1GGG4T-3') guanine residues, respectively. In Escherichia coli, the frequency induced -1 frameshift mutations was strongly dependent on position modification: pS3G-G3 approximately 100-fold 10-fold more mutagenic than pS3G-G1 pS3G-G2, respectively; pSG4-G4 600-fold pSG4-G1. Mutagenesis SOS-dependent markedly reduced in bacteria were...

Mutations are permanent DNA sequence changes that can be induced when replication occurs on a damaged template. In Escherichia coli, the process of translesion synthesis past lesion hinders requires induction SOS-controlled gene products, among which those umuDC operon. To study in vivo, we have constructed single-stranded vectors containing single 2-acetylaminofluorene adducts located within -1 and -2 frameshift mutation hot spots formed by short repetitive sequences. These strongly hinder...

The Nar I sequence represents a strong mutation hot spot for - 2 frameshift mutations induced by N-2-acetylaminofluorene (AAF), chemical carcinogen. Only when bound to the third (underlined) guanine (5′-GGCGCC → GGCC) can AAF trigger mutations, suggesting involvement of slipped replication intermediate with two-nucleotide bulge. While base substitutions UV light or abasic sites require DNA polymerase V (Pol V; umuDC), AAF-induced pathway requires II, polB gene product. Interestingly,...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTDNA Sequence Determinants of Carcinogen-Induced Frameshift MutagenesisRita L. Napolitano, Iain B. Lambert, and Robert P. FuchsCite this: Biochemistry 1994, 33, 6, 1311–1315Publication Date (Print):February 15, 1994Publication History Published online1 May 2002Published inissue 15 February 1994https://pubs.acs.org/doi/10.1021/bi00172a004https://doi.org/10.1021/bi00172a004research-articleACS PublicationsRequest reuse permissionsArticle...

Single-stranded DNA vectors containing single adducts offer a unique opportunity to study the biochemistry and genetics of trans lesion synthesis, process during which polymerase synthesizes across lesion. We describe new general strategy produce high-quality single-stranded plasmids adduct within predetermined sequence context starting with short oligonucleotide interest. These are isolated from corresponding double-stranded constructs by selective enzymatic degradation in vitro nonadducted...

Translesion synthesis at replication-blocking lesions requires the induction of proteins that are controlled by SOS system in Escherichia coli. Of identified so far, UmuD', UmuC, and RecA* were shown to facilitate replication across UV-light-induced lesions, yielding both error-free mutagenic translesion-synthesis products. Similar UV N-2-acetylaminofluorene (AAF), a chemical carcinogen forms covalent adducts C8 position guanine residues, is strong lesion. Frameshift mutations induced...

It is generally assumed that most point mutations are fixed when damage containing template DNA undergoes replication, either right at the fork or behind during gap filling. Here we provide genetic evidence for a pathway, dependent on Nucleotide Excision Repair, induces processing closely spaced lesions. This referred to as Repair-induced Mutagenesis (NERiM), exhibits several characteristics distinct from occur within course of replication: i) following UV irradiation, NER-induced much more...

The repair of singlet oxygen (1O2)-induced DNA lesions requires several enzymes the nucleotide and base excision pathways, including exonuclease III endonuclease IV that are known apurinic/apyrimidinic-endonucleases in Escherichia coli. In order to better understand relevance on these lesions, we investigated mutagenic events result from replication a 1O2-damaged plasmid an exonuclease-deficient host (xth). mutation spectrum tRNA supF gene target indicated absence does not change types...

The NarI sequence represents a strong mutation hot spot for -2 frameshift mutations induced by N-2-acetylaminofluorene (AAF), chemical carcinogen. Only when bound to the third (underlined) guanine (5'-GGCGCC-->GGCC) can AAF trigger mutations, suggesting involvement of slipped replication intermediate with two-nucleotide bulge. While base substitutions UV light or abasic sites require DNA polymerase V (Pol V; umuDC), AAF-induced pathway requires II, polB gene product. Interestingly,...

The repair of singlet oxygen (1O2)-induced DNA lesions requires several enzymes the nucleotide and base excision pathways, including exonuclease III endonucle-ase IV that are known apurinic/apyrunidinic-endonucleases in Escherichia coli. In order to better understand relevance on these lesions, we investigated mutagenic events result from replication a 1O2-damaged plasmid an exonuclease-deflcient host (xth). mutation spectrum tRNA supF gene target indicated absence does not change types...