Studies of diversification of plasmid replication regions by genetic recombination

通过基因重组使质粒复制区域多样化的研究

• 批准号: 04454001
• 负责人: MIZOBUCHI Kiyoshi
• 金额: $ 4.16万
• 依托单位: University of Electro-Communications
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (B)
• 财政年份: 1992
• 资助国家: 日本
• 起止时间: 1992 至 1994
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-04454001/
• 关键词: IncIalpha and IncFII plasmids; replication region; diversification; reciprocal recombination; RNA structures; Replication control; RNAの高次構造; 複製領域の多様性; 複製装置システム; 複製領域の構造; P307プラスミド; ColIb-P9プラスミド; R100プラスミド; キメラレプリコン; 遺伝的組換え; IncFICプラスミド

Living things are information systems that are highly organized by a variety of genes. In this project, we have studied how replication systems of some bacterial plasmids diverged during the course of evolution. The basic replicons of bacterial plasmids consist of two sets of genetic systems, the replication-structural system and the replication control system. Comparison of nucleotide sequences suggested that plasmids P307 (IncFI) and pMU2200 (IncZ) were generated by reciprocal recombination between ancestors of R100 (IncFII) and ColIb-P9 (IncIalpha) , or vice versa. The plasmids of each pair, P307/pMU2200 and R100/ColIb-P9, are structurally unrelated to each other. Based on this information, we constructed in vitro and analyzed P307-like chimeric replicons from ColIb-P9 and R100. When the replication-structural region of ColIb-P9 was combined with the whole replication control region of R100, the resultant replicon replicated stably as R100 did. These results revealed that the basic replicons of the plasmids diverged by exchanging their replication control systems. Thus, we propose that the replication control systems of plasmids, in some cases, evolved independently of their structural systems, although these two systems work together for maintaining the replication functions. We also studied that the reciprocal recombination was specified by the unique secondary structures of RNA involved in the control of expression of the genes encoding the replication initiator proteins.

生物是由各种基因高度组织的信息系统。在这个项目中，我们研究了一些细菌质粒的复制系统在进化过程中是如何分化的。细菌质粒的基本复制子由两套遗传系统组成，即复制结构系统和复制控制系统。核苷酸序列的比较表明，质粒P307（IncFI）和pMU 2200（IncZ）是通过R100（IncPII）和ColIb-P9（IncIalpha）的祖先之间的相互重组产生的，反之亦然。每对质粒P307/pMU 2200和R100/ColIb-P9在结构上彼此不相关。基于这些信息，我们在体外构建并分析了来自ColIb-P9和R100的P307样嵌合复制子。当ColIb-P9的复制结构区与R100的整个复制控制区结合时，所得复制子像R100一样稳定复制。这些结果表明，质粒的基本复制子通过交换它们的复制控制系统而分化。因此，我们提出，在某些情况下，质粒的复制控制系统，独立于其结构系统的演变，虽然这两个系统一起工作，以维持复制功能。我们还研究了相互重组是由参与控制复制起始蛋白编码基因表达的RNA的独特二级结构所指定的。

项目成果

Atsushi Mori: "A transcriptional terminator signal necessary for plasmid ColIb-P9 replication" Mol.Microbiol.12, (in press). (1995)

Atsushi Mori：“质粒 ColIb-P9 复制所必需的转录终止子信号”Mol.Microbiol.12，（正在印刷中）。

Akihiko Kato: "Evolution of the replication regions of IncIalpha and IncFII plasmids by exchanging their replication control systems" DNA Research. 1. 201-212 (1994)

加藤明彦 (Akihiko Kato)：“通过交换复制控制系统来进化 IncIalpha 和 IncFII 质粒的复制区域”DNA 研究。

Shu-ichi Nakayama: "Cloning, sequencing, and expression of bacteriophage BF23 late genes 24 and 25 encoding tail proteins" J.Bacteriol.176. 7280-7290 (1994)

Shu-ichi Nakayama：“编码尾部蛋白的噬菌体 BF23 晚期基因 24 和 25 的克隆、测序和表达”J.Bacteriol.176。

Akihiro Iida: "Identification and characterization of the tktB gene encoding a second transketolase in Escherichia coli" J.Bacteriol.175. 5375-5383 (1993)

Akihiro Iida：“大肠杆菌中编码第二种转酮酶的 tktB 基因的鉴定和表征”J.Bacteriol.175。

山田 秀明,別府 輝彦,深沢 俊夫編: "微生物の機能開発" 学会出版センター, 330 (1992)

山田秀明、别府辉彦、深泽俊夫（编）：《微生物的功能开发》学会出版中心，330（1992）