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Homologous DNA interactions in the evolution of genes and species

基因和物种进化中的同源 DNA 相互作用

基本信息

批准号：
10044062
负责人：
KOBAYASHI Ichizo
金额：
$ 1.54万
依托单位：
The University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for international Scientific Research
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 1999
项目状态：
已结题

项目摘要

Kobayashi saw Radman and Kowalczykowski in France in 1998. Kobayashi saw Radman in USA in 1998. In 1999, Radman visited Japan and gave a lecture in the annual meeting of Biochemistry society of Japan. In 1999, Kowalczykowski visited Japan and gave a talk in 3R symposium. The following lists achievements, primarily from Kobayashi laboratory, which are most related to this collaboration.(1) Bacterial homologous recombination in fight and collaboration with selfish restriction modification genes. Several rec genes --- recA, recBC, ruvAB, ruvC, recG --- were found to defend bacteria against the RM gene complexes by repairing cleaved chromosomes, as detected by pulsed-field gel electrophoresis. Genetic analysis indicates that the interaction of Chi sequence with RecBCD enzyme, plays an important role. In a paper published together with Kowalczykowski lab, a mutant RecBCD enzyme was shown be altered in sequence recognition in vitro.(2) Alleviation and enhancement of type III restriction by b … More acteriophage and host homologous recombination functions. recET genes of Rac prophage and red genes of bacteriophage lambda were shown to alleviate type III restriction by EcoP1 and EcoP15. In contrast, RecBCD pathway stimulated type III restriction.(3) Spontaneous accumulation of huge linear chromosomes in recombination-defective mutants of Escherichia coli. Huge linear forms of E.coli chromosome that are produced by spontaneous breakage of its circular forms were detected by pulsed-field gel electrophoresis in various recombination-related mutants.(4) Why is a mismatch repair gene present? Some bacteria carry"orphan"DNA methyltransferase that is not paired with a restriction enzyme. Dcm in some strains of E.coli K-12 recognizing CC(A/T)GG provides one example. Its role has not been clear. We demonstrated that Dcm serves as molecular vaccine protecting the genome from post-segregational killing programmed by EcoRII, an RM system recognizing the same sequence.(5) Mismatch and homologous recombination. The"random walk"model was extended to explain the effects of sequence divergence and mismatch repair system. Less

1998年，小林在法国见到了拉德曼和科瓦尔奇科斯基。1998年，小林在美国见到了拉德曼。1999年，拉德曼访问了日本，并在日本生物化学学会年会上发表了演讲。 1999年，Kowalczykowski访问日本并在3R研讨会上发表报告。以下列出了与本次合作最相关的主要来自小林实验室的成果。(1)细菌同源重组与自私限制性修饰基因的斗争和合作。通过脉冲场凝胶电泳检测发现，几种rec基因——recA、recBC、ruvAB、ruvC、recG——可以通过修复断裂的染色体来保护细菌免受RM基因复合物的侵害。遗传分析表明Chi序列与RecBCD酶的相互作用起着重要作用。在与 Kowalczykowski 实验室共同发表的一篇论文中，突变型 RecBCD 酶被证明在体外序列识别中发生改变。(2) 通过噬菌体和宿主同源重组功能减轻和增强 III 型限制。 Rac 原噬菌体的 recET 基因和 lambda 噬菌体的 red 基因被证明可以减轻 EcoP1 和 EcoP15 的 III 型限制。相反，RecBCD途径刺激III型限制。(3)大肠杆菌重组缺陷突变体中巨大线性染色体的自发积累。通过脉冲场凝胶电泳在各种重组相关突变体中检测到由其圆形形式自发断裂而产生的巨大线性形式的大肠杆菌染色体。(4)为什么存在错配修复基因？一些细菌携带不与限制酶配对的“孤儿”DNA甲基转移酶。某些识别 CC(A/T)GG 的大肠杆菌 K-12 菌株中的 Dcm 就是一个例子。其作用尚不清楚。我们证明Dcm可以作为分子疫苗，保护基因组免受EcoRII（一种识别相同序列的RM系统）编程的分离后杀伤。（5）错配和同源重组。扩展“随机游走”模型来解释序列分歧和错配修复系统的影响。较少的