Baril C, Herrmann J L, Richaud C, Margarita D, Girons I S
Unité de Bactériologie Moléculaire et Médicale, Institut Pasteur, Paris, France.
J Bacteriol. 1992 Dec;174(23):7566-71. doi: 10.1128/jb.174.23.7566-7571.1992.
Leptospira interrogans is a pathogenic bacterium with a low G+C content (34 to 39%). The restriction enzymes NotI, AscI, and SrfI cut the chromosome of L. interrogans serovar icterohaemorrhagiae into 13, 3, and 5 fragments separable by one- and two-dimensional pulsed-field gel electrophoresis (PFGE). The genome is composed of a circular 4.6-Mbp chromosome and a 0.35-Mbp extrachromosomal element. A physical map of the chromosome was constructed for NotI, AscI, and SrfI by using single and double digests, or partial NotI digests obtained at random or by cross-protection of NotI sites by FnuDII methylase, and linking clones. rRNA genes were found to be widely scattered on the chromosome.
问号钩端螺旋体是一种G+C含量较低（34%至39%）的致病细菌。限制性内切酶NotI、AscI和SrfI可将黄疸出血型问号钩端螺旋体的染色体切割成13、3和5个片段，这些片段可通过一维及二维脉冲场凝胶电泳（PFGE）分离。该基因组由一条4.6兆碱基对的环状染色体和一个0.35兆碱基对的染色体外元件组成。通过使用单酶切和双酶切、随机获得的部分NotI酶切或通过FnuDII甲基化酶对NotI位点的交叉保护以及连接克隆，构建了NotI、AscI和SrfI的染色体物理图谱。发现rRNA基因广泛散布于染色体上。
