Contiguous 2,2,4-triamino-5(2H)-oxazolone obstructs DNA synthesis by DNA polymerases α, β, η, ι, κ, REV1 and Klenow Fragment exo-, but not by DNA polymerase ζ.
Guanine is the most easily oxidized of the four DNA bases, and contiguous guanines (GG) in a sequence are more readily oxidized than a single guanine in a sequence. Continued oxidation of GGs results in a contiguous oxidized guanine lesion. Two contiguous 2,5-diamino-4H-imidazol-4-ones, an oxidized form of guanine that hydrolyses to 2,2,4-triamino-5(2H)-oxazolone (Oz), are detected following the oxidation of GG. In this study, we analysed translesion synthesis (TLS) across two contiguous Oz molecules (OzOz) using Klenow Fragment exo(-) (KF exo(-)) and DNA polymerases (Pols) α, β, ζ, η, ι, κ and REV1. We found that KF exo(-) and Pols α, β, ι and REV1 inserted one nucleotide opposite the 3' Oz of OzOz and stalled at the subsequent extension, and that Pol κ incorporated no nucleotide. Pol η only inefficiently elongated the primer up to full-length across OzOz; the synthesis of most DNA strands stalled at the 3' or 5' Oz of OzOz. Surprisingly, however, Pol ζ efficiently extended the primer up to full-length across OzOz, unlike the other DNA polymerases, but catalysed error-prone nucleotide incorporation. We therefore believe that Pol ζ is required for efficient TLS of OzOz. These results show that OzOz obstructs DNA synthesis by DNA polymerases except Pol ζ.
Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, 1314-1, Shido, Sanuki, Kagawa 769-2193, Japan and.
Masayo
M
Suzuki
Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, 1314-1, Shido, Sanuki, Kagawa 769-2193, Japan and kkino@kph.bunri-u.ac.jp.
Katsuhito
K
Kino
Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, 1314-1, Shido, Sanuki, Kagawa 769-2193, Japan and.
Taishu
T
Kawada
Faculty of Science, Department of Chemistry, Shizuoka University, 836 Ohya, Suruga, Shizuoka 422-8529, Japan.
Takanori
T
Oyoshi
Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, 1314-1, Shido, Sanuki, Kagawa 769-2193, Japan and.
Masayuki
M
Morikawa
Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, 1314-1, Shido, Sanuki, Kagawa 769-2193, Japan and.
Takanobu
T
Kobayashi
Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, 1314-1, Shido, Sanuki, Kagawa 769-2193, Japan and.
Hiroshi
H
Miyazawa
D004247:DNA / Q000096:biosynthesis*; D004249:DNA Damage; D004256:DNA Polymerase I / Q000737:chemistry; D017931:DNA Primers / Q000378:metabolism; D004260:DNA Repair; D004261:DNA Replication; D004259:DNA-Directed DNA Polymerase / Q000737:chemistry*; D057075:Enzyme Assays; D006146:Guanidines / Q000737:chemistry*; D006147:Guanine / Q000737:chemistry*; D006801:Humans; D009687:Nuclear Proteins / Q000737:chemistry*; D009713:Nucleotidyltransferases / Q000737:chemistry*; D010084:Oxidation-Reduction; D000099270:Y-Family DNA Polymerases
D004247:DNA; D004256:DNA Polymerase I; D017931:DNA Primers; D004259:DNA-Directed DNA Polymerase; D006146:Guanidines; D006147:Guanine; D009687:Nuclear Proteins; D009713:Nucleotidyltransferases; C000607919:2,2,4-triamino-5(2H)-oxazolone; C429004:REV1 protein, human; D000099270:Y-Family DNA Polymerases
2,2,4-triamino-5(2H)-oxazolone; DNA polymerase; contiguous damage; oxidation of guanine; translesion synthesis