Recognition and repair of 2-aminofluorene- and 2-(acetylamino)fluorene-DNA adducts by UVRABC nuclease

Journal Article · Tue Jul 11 00:00:00 EDT 1989 · Biochemistry; (USA)

DOI:https://doi.org/10.1021/bi00440a018· OSTI ID:5060369

Pierce, J R; Case, R; Tang, Moonshong ^[1]

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1. Univ. of Texas, Smithville (USA)

Recognition of damage induced by N-hydroxy-2-aminofluorene (N-OH-AF) and N-acetoxy-2-(acetylamino)fluorene (NAAAF) in both {phi}X174 RFI supercoiled DNA and a linear DNA fragment by purified UVRA, UVRB, and UVRC proteins was investigated. The authors have previously demonstrated that N-OH-AF and NAAAF treatments produce N-(deoxyguanosin-8-yl)-2-aminofluorene (dG-C8-AF) and N-(deoxyguanosin-8-yl)-2-(acetylamino)fluorene (dG-C8-AAF), respectively, in DNA. Using a piperidine cleavage method and DNA sequence analysis, they have found that all guanine residues can be modified by N-OH-AF and NAAAF. These two kinds of adducts have different impacts on the DNA helix structure; while dG-C8-AF maintains the anti configuration, dG-C8-AAF is in the syn form. {phi}X174 RF DNA-Escherichia coli transfection results indicate that while the uvrA, uvrB, and uvrC gene products are needed to repair dG-C8-AAF, the uvrC, but not the uvrA or uvrB gene products, is needed for repair of dG-C8-Af. However, they have found that in vitro the UVRA, UVRB, and UVRC proteins must work in concert to nick both dG-C8-AF and dG-C8-AAF. In general, the reactions of UVRABC nuclease toward dG-C8-AF are similar to those toward dG-C8-AAF; it incises seven to eight nucleotides from the 5{prime} side and three to four nucleotides from the 3{prime} side of the DNA adduct. Evidence is presented to suggest that hydrolysis on the 3{prime} and 5{prime} sides of the damaged base by UVRABC nuclease is not simultaneous and that at least occasionally hydrolysis occurs only on the 3{prime} side or on the 5{prime} side of the damage site. The possible mechanisms of UVRABC nuclease incision for AF-DNA are discussed.

• OSTI ID: 5060369
• Journal Information: Biochemistry; (USA), Vol. 28:14; ISSN 0006-2960
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
DNA ADDUCTS
BIOLOGICAL REPAIR
FLUORENE
BIOLOGICAL EFFECTS
NUCLEASES
BIOCHEMISTRY
BACTERIOPHAGES
CONDENSED AROMATICS
ESCHERICHIA COLI
GENES
ULTRAVIOLET RADIATION
ADDUCTS
AROMATICS
BACTERIA
BIOLOGICAL RECOVERY
CHEMISTRY
ELECTROMAGNETIC RADIATION
ENZYMES
ESTERASES
HYDROCARBONS
HYDROLASES
MICROORGANISMS
ORGANIC COMPOUNDS
PARASITES
PHOSPHODIESTERASES
RADIATIONS
RECOVERY
REPAIR
VIRUSES
550201* - Biochemistry- Tracer Techniques