Insertion of specific bases during DNA synthesis past the oxidation-damaged base 8-oxodG

  title={Insertion of specific bases during DNA synthesis past the oxidation-damaged base 8-oxodG},
  author={Shinya Shibutani and Masaru Takeshita and Arthur P. Grollman},
OXIDATIVE damage to DNA, reflected in the formation of 8-oxo- 7-hydrodeoxyguanosine (8-oxodG)1,2, may be important in mutagenesis, carcinogenesis and the ageing process3,4. Kuchino et al. studied DNA synthesis on oligodeoxynucleotide templates containing 8-oxodG, concluding that the modified base lacked base pairing specificity and directed misreading of pyrimidine residues neighbouring the lesion5. Here we report different results, using an approach in which the several products of a DNA… 

Insertion of dGMP and dAMP during in vitro DNA synthesis opposite an oxidized form of 7,8-dihydro-8-oxoguanine.

Results demonstrate that an oxidized form of 8-oxoG, possibly guanidinohydantoin, may direct misreading and misinsertion of dNTPs during DNA synthesis.

Characterization of DNA with an 8-oxoguanine modification

Thermodynamic studies show that oxoG destabilizes DNA (ΔΔG of 2–8 kcal mol−1 over a 16–116 mM NaCl range) due to a significant reduction in the enthalpy term, and has a profound effect on the level and nature of DNA hydration indicating that the environment around anOxoG•C is fundamentally different than that found at G•C.

Structure of Human DNA Polymerase κ Inserting dATP Opposite an 8-OxoG DNA Lesion

The structure presented here is the first for a eukaryotic translesion synthesis (TLS) DNA polymerase with an 8-oxoG:A base pair in the active site and provides a basis for why Polκ is more efficient at inserting an A opposite the lesion than other Y-family DNA polymerases.

Base excision repair synthesis of DNA containing 8-oxoguanine in Escherichia coli

The results indicate the biological significance of the glycosylase and apurinic/ apyrimidinic lyase activities of Fpg, in concert with 3' phosphatase(s) to create an appropriately gapped substrate for efficient BER synthesis of DNA containing 8-oxo-G.

DNA polymerase minor groove interactions modulate mutagenic bypass of a templating 8-oxoguanine lesion

The results demonstrate that the incoming nucleotide is unable to induce a syn-8-oxoG conformation without minor groove DNA polymerase interactions that influence templating (anti-/syn-equilibrium) of 8-OxoG while modulating fidelity.

Action of Mitochondrial DNA Polymerase at Sites of Base Loss or Oxidative Damage (*)

Both mitochondrial DNA lesions have the prospect of causing high rates of mutation during mtDNA replication and the effects of these lesions on the 3′ 5′ exonuclease proofreading activity of DNA polymerase were investigated.

Recognition and Repair of 8‐Oxoguanine and Formamidopyrimidine Lesions in DNA a

Plasmid vectors containing a single lesion were used to establish the mutational frequency and specificity of 9oxodG in bacteria and mammalian cells; 9-OxodG is weakly mutagenic in both systems; G:C{l_arrow}T:A transversions are targeted to the site of the lesion.



Misreading of DNA templates containing 8-hydroxydeoxyguanosine at the modified base and at adjacent residues

The syn-thetic oligodeoxynucleotides, with or without an 8-OH-dG residue in a specified position, were chemically synthesized and used as templates for DNA synthesis under the conditions of the dideoxy chain termination sequencing method.

Structural and conformational analyses of 8-hydroxy-2'-deoxyguanosine.

Determination of the chemical shifts and the nuclear Overhauser enhancements of the N1 and N7 resonances in the proton-decoupled 15N NMR spectrum indicated that both nitrogens were indeed protonated at neutral pH and provided evidence that this DNA adduct contains a C6-keto group at physiological pH.

Mechanistic studies of ionizing radiation and oxidative mutagenesis: genetic effects of a single 8-hydroxyguanine (7-hydro-8-oxoguanine) residue inserted at a unique site in a viral genome.

T4 RNA ligase was used to construct a deoxypentanucleotide containing a single 8-hydroxyguanine residue, which is one of the putatively mutagenic DNA adducts produced by oxidants and ionizing radiation.

Urinary 8-hydroxy-2'-deoxyguanosine as a biological marker of in vivo oxidative DNA damage.

Analysis of urine from three species by this method indicates that mice excrete approximately 3.3-fold more 8-hydroxy-2'-deoxyguanosine than humans, a result that supports the proposal that oxidative damage to DNA increases in proportion to species-specific basal metabolic rates.

Hydroxylation of deoxyguanosine at the C-8 position by ascorbic acid and other reducing agents.

The C-8 position of deoxyguanosine (dGuo) was hydroxylated by ascorbic acid in the presence of oxygen (O2) in 0.1 M phosphate buffer in high yield with remarkably enhanced addition of hydrogen peroxide (H2O2).

Further studies on calf thymus DNA polymerase delta purified to homogeneity by a new procedure.

DNA polymerase delta from calf thymus has been purified to apparent homogeneity by a new procedure which utilizes hydrophobic interaction chromatography with phenyl-Sepharose at an early step to

Expression of human DNA polymerase beta in Escherichia coli and characterization of the recombinant enzyme.

The recombinant protein had about the same DNA polymerase specific activity as beta-polymerase purified from mammalian tissues, and template-primer specificity and immunological properties of the recombinant polymerase were similar to those of natural beta- polymerases.