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浑球红细菌(R.sphaeroides)glnBA基因克隆及其物理图谱

韩涛, 吴永强, 宋鸿遇

中科院上海植物生理研究所.上海200032

摘要

从浑球红细菌的基因文库中筛选到pHT3、pHT10及pHT35三个阳性克隆,其中质粒pHT10与pH35能遗传互补荚膜红细菌的谷氨酰胺缺陷型G29,使其GS酶及固氮酶活性得到恢复。对质粒pHT10上的glnA同源片段进行了亚克隆和限制性内切酶图谱分析,确定了浑球红细菌glnB与glnA之间存在连锁关系。

关键词： 浑球红细菌; 谷氨酰胺合成酶; 固氮; glnA基因; glnB基因

The cloning and physical map of glnBA genes of Rhodobacter sphaeroides

Han Tao, Wu Yongqiang, Song Hongyu

Shanghai Institute of Plant Physiology,The Chinese Academy of Scienese.Shanghai 200032

Abstract

The purple non-suphur photosynthetic bacterium Rhodobacter sphaeroides fixes nitrogen microaerobically or anaerobically when the level of intracellular fixed nirogen is limited.Using the glnA gene of R. capsulata as probe, three positive clones from the gene libray of R.sphaeroides,named pHT3,pHT10 and pH35 were obtained.When they were conjugated into G29(Gln-mutant of R. capsulata),the strains with pHT10 and pHT35 could grow on RCVB minimal medium and restore the activity of glutamine synthetase and nitrogenase of G29.The results showed that the plasmids pHT10 and pH35 included the complete glnA gene of R.sphaeroides.Then two glnA homologous fragments of plasmid pHT10,3.5kb-BamH Ⅰand 2.7 kb-Pst I fragments were subdoned.By restriction analysis and Southern hybhridization,the sites of glnBA genes on the two fragments were found .The results showed that the special structure of glnB and glnA on one cluster maight be related to the characteristics of nitrogen fixation of this kind of bacterumm.

Key words: R. sphaeroides;Glutomine synthetase;Nitrogen fixation;GlnA gene;GlnB gene

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引用本文：

韩涛, 吴永强, 宋鸿遇. 浑球红细菌(R.sphaeroides)glnBA基因克隆及其物理图谱[J]. 生理学报 1996; 48 (2): .

Han Tao, Wu Yongqiang, Song Hongyu. The cloning and physical map of glnBA genes of Rhodobacter sphaeroides. Acta Physiol Sin 1996; 48 (2): (in Chinese with English abstract).