Translesion synthesis by yeast DNA polymerase ζ from templates containing lesions of ultraviolet radiation and acetylaminofluorene
Translesion synthesis by yeast DNA polymerase ζ from templates containing lesions of ultraviolet radiation and acetylaminofluorene
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DOI：
10.1093/nar/29.13.2875
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发表时间：
2001-07-01
影响因子：
14.9
通讯作者：
Wang, ZG
中科院分区：
文献类型：
--
作者：
Guo, DY;Wu, XH;Wang, ZG
在酿酒酵母中，主要病变旁路途径需要 DNA 聚合酶 zeta (Pol zeta)。为了帮助了解 Pol zeta 在病变旁路中的作用，我们针对几种 DNA 病变对这种聚合酶进行了体外生化分析。纯化的酵母 Pol zeta 在模板 TT (6-4) 光产物对面进行有限的跨损伤合成，以相似的效率掺入 A 或 T，但在 3'T 对面的 G) 频率较低，并且主要在 5'T 对面掺入 A，纯化的酵母 Pol zeta 主要掺入与乙酰氨基芴 (AAF) 加合鸟嘌呤相对的 G。然而，损伤显着抑制了随后的延伸。此外，酵母 Pol zeta 以不同的效率催化来自与 AAF-鸟嘌呤和 TT (6-4) 光产物的 3'T 相对退火的引物的延伸 DNA 合成。当 A 或 C 与 AAF-鸟嘌呤相对时，以及当 G 与 TT (6-4) 光产物的 3 ' T 相对时，延伸合成效率更高。相比之下，顺式 TT 二聚体的 3'T 完全阻断了纯化的酵母 Pol zeta，而 5'T 很容易被绕过。这些结果支持以下 Pol zeta 双功能模型。首先，Pol zeta 催化 AAF-鸟嘌呤和 TT (6-4) 光产物相反的核苷酸掺入，但效率有限。其次，更有效地绕过这些损伤可能需要通过其他 DNA 聚合酶掺入核苷酸，然后通过 Pol zeta 合成延伸 DNA。
In the yeast Saccharomyces cerevisiae, DNA polymerase zeta (Pol zeta) is required in a major lesion bypass pathway. To help understand the role of Pol zeta in lesion bypass, we have performed in vitro biochemical analyses of this polymerase in response to several DNA lesions. Purified yeast Pol zeta performed limited translesion synthesis opposite a template TT (6-4) photoproduct, incorporating A or T with similar efficiencies land less frequently G) opposite the 3 ' T, and predominantly A opposite the 5 ' T, Purified yeast Pol zeta predominantly incorporated a G opposite an acetylaminofluorene (AAF)-adducted guanine, The lesion, however, significantly inhibited subsequent extension. Furthermore, yeast Pol zeta catalyzed extension DNA synthesis from primers annealed opposite the AAF-guanine and the 3 ' T of the TT (6-4) photoproduct with varying efficiencies. Extension synthesis was more efficient when A or C was opposite the AAF-guanine, and when G was opposite the 3 ' T of the TT (6-4) photoproduct. In contrast, the 3 ' T of a cis-syn TT dimer completely blocked purified yeast Pol zeta, whereas the 5 ' T was readily bypassed. These results support the following dual-function model of Pol zeta. First, Pol zeta catalyzes nucleotide incorporation opposite AAF-guanine and TT (6-4) photoproduct with a limited efficiency. Secondly, more efficient bypass of these lesions may require nucleotide incorporation by other DNA polymerases followed by extension DNA synthesis by Pol zeta.