Molecular Mechanisms of Radiation and Chemical Mutagenesis

辐射和化学诱变的分子机制

• 批准号: 02454548
• 负责人: SHINAGAWA Hideo
• 金额: $ 4.29万
• 依托单位: Osaka University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (B)
• 财政年份: 1990
• 资助国家: 日本
• 起止时间: 1990 至 1992
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-02454548/
• 关键词: Radiation; Mutagenesis; UmuD protein; MucA protein; DNA polymerase II; polB gene; RuvA, B, C proteins; Holliday structure; DNA修復; DNA組換え; DNAポリメラーゼ; RuvAタンパク; RuvBタンパク; DNA損傷; ruvA・B・C遺伝子; DNAポリメラ-ゼII; SOS反応; DNAポリメラ-ゼ; umuD,C遺伝子; mucA,

To elucidate molecular mechanisms of radiation and chemical mutagenesis, we have studiedbiochemical properties of the products of the genes which are known to be involved in mutagenesis in Escherichia coli. The major accomplishments of this project are as follows.1. RecA protein activated in the DNA-damaged cell promotes cleavage of UnuD and MucA proteins and thereby activates these proteins for mutagenesis.2. We demonstrated that the polB gene is negatively regulated by LexA repressor (SOS regulation) and that DNA polymerase II encoded by polB is structurally and functionally homologous to replicative DNA polymerases of eukaryotes.3. We have proved that a RuvA tetramer and RuvB form a stable complex and the complex interacts specifically with the Holliday structure, an intermediate of homologous recombination, and promotes branch migration.4. We demonstrated biochemically that RuvC protein is a specific endonuclease that resolves the Holliday junction.

为了阐明辐射和化学诱变的分子机制，我们研究了已知参与大肠杆菌诱变的基因产物的生化特性。本项目的主要成果如下： 1．在DNA损伤的细胞中激活的RecA蛋白促进UnuD和MucA蛋白的裂解，从而激活这些蛋白进行诱变。2．我们证明polB基因受到LexA阻遏物（SOS调节）的负调控，并且polB编码的DNA聚合酶II在结构和功能上与真核生物的复制DNA聚合酶同源。3．我们证明RuvA四聚体和RuvB形成稳定的复合物，该复合物与同源重组中间体Holliday结构特异性相互作用，促进分支迁移。 4．我们通过生化方法证明了 RuvC 蛋白是一种能够解析霍利迪连接体的特异性核酸内切酶。

项目成果

Shinagawa,H: "SOS-inducible DNA polymerase II of E.coli is homologous to replicative DNA polymerase of eukaryotes." Biochimie. 73. 433-435 (1991)

Shinakawa,H：“大肠杆菌的 SOS 诱导型 DNA 聚合酶 II 与真核生物的复制性 DNA 聚合酶同源。”

Shiba,T.: "Proteolytic processing of MucA protein in SOS mutagenesis:both processed and unprocessed MucA may be active in the mutagenesis." Mol.Gen.Genet.224. 169-176 (1990)

Shiba,T.：“SOS 诱变中 MucA 蛋白的蛋白水解加工：加工过的和未加工过的 MucA 都可能在诱变中具有活性。”

Shiba,T.,H.Iwasaki,A.Nakata,and H.Shinagawa: "Proteolytic processing of MucA protein in SOS mutagenesis:both processed and unprocessed MucA may be active in the mutagenesis" Mol.Gen.Genet.224. 169-176 (1990)

Shiba,T.,H.Iwasaki,A.Nakata,and H.Shinakawa：“SOS 诱变中 MucA 蛋白的蛋白水解加工：加工过的和未加工过的 MucA 可能在诱变中具有活性”Mol.Gen.Genet.224。

Iwasaki,H.: "Escherichia coli RuvC protein is an endonuclease that resolves the Holliday structure." EMBO J.10. 4381-4389 (1991)

Iwasaki, H.：“大肠杆菌 RuvC 蛋白是一种解析 Holliday 结构的核酸内切酶。”

Shinagawa,H.: "Properties of the Escherichia coli RuvB proteins involved in DNA repair,recombination and mutagenesis." Biochimie. 73. 505-507 (1991)

Shinakawa, H.：“大肠杆菌 RuvB 蛋白参与 DNA 修复、重组和诱变的特性。”