Physical and genetic maps of the Leptospira interrogans serovar icterohaemorrhagiae strain Ictero No. 1 chromosome and sequencing of a 19-kb region of the genome containing the 5S rRNA gene
Physical and genetic maps of the Leptospira interrogans serovar icterohaemorrhagiae strain Ictero No. 1 chromosome and sequencing of a 19-kb region of the genome containing the 5S rRNA gene
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DOI：
10.1016/s0378-1119(98)00277-7
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发表时间：
1998-07-17
期刊：
影响因子：
3.5
通讯作者：
Fukunaga, M
中科院分区：
文献类型：
--
作者：
Takahashi, Y;Akase, K;Fukunaga, M
我们报告了问号钩端螺旋体黄疸出血型血清型菌株Iceberg 1号染色体的物理和遗传图谱的构建，使用脉冲保持凝胶电泳酶SrfI，AscI，FseI和NotI消化产生的DNA片段，并使用相互杂交。我们还测定了致病性钩端螺旋体的19 kb DNA片段，其中包括一个58 rRNA（rrf）基因。估计菌株Icebra No.1的染色体大小为4673 kb，发现与钩端螺旋体菌株凡尔登（黄疸出血血清型）和RZ 11（波莫纳血清型）的染色体大小相似。菌株凡尔登和RZ 11携带一个350-kb的小复制子（微型染色体），菌株Iceberg No.1也含有与染色体相同的分子。菌株Icestrium No. 1和凡尔登的物理图谱几乎相同，所选基因的位置也是如此，除了一个16 S rRNA基因的位置。总体而言，黄疸出血血清型菌株的遗传组织似乎是保守的。在测序区域，我们鉴定了10个推定的ORF和1个rrf序列，并且转录方向都相同。同源性分析表明，该基因与流感嗜血杆菌的苹果酸酶和大肠杆菌的延胡索酸水合酶（orf J）具有很高的相似性。在测序区域中由ORF编码的其余推定产物与数据库中包含的蛋白质几乎没有相似性，被认为是未知蛋白质。(C)1998 Elsevier Science B.V.保留所有权利。
We report the construction of physical and genetic maps of the chromosome of Leptospira interrogans serovar icterohaemorrhagiae strain Ictero No. 1 using pulsed-held gel electrophoresis of DNA fragments generated by digestion with enzymes SrfI, AscI, FseI, and NotI and using reciprocal hybridization. We also sequenced the 19-kilobase (kb) DNA segment including the one gene for 58 rRNA (rrf) of pathogenic Leptospira. The size of the chromosome of the strain Ictero No. 1 was estimated to be 4673 kb and was found to be similar to those of the chromosomes of the leptospira strains Verdun (serovar icterohaemorrhagiae) and RZ11 (serovar pomona). The strains Verdun and RZ11 carry a small 350-kb replicon (minichromosome), and the strain Ictero No. 1 also contained the same kind of molecule together with the chromosome. The physical maps of the strains Ictero No. 1 and Verdun were almost identical, as were the locations of the selected genes, except for the location of one of the 16S rRNA genes. Overall, the genetic organization appeared to be conserved within the serovar icterohaemorrhagiae strains. In the sequenced region, we identified 10 putative ORFs and one rrf sequence, and the transcription orientations were all the same. A homology search for the products deduced from the sequenced data revealed that the orf H exhibited high similarity to malic acid enzyme of Haemophilus influenzae and fumarate hydratase of Escherichia coli (orf J). The rest of the putative products encoded by ORFs in the sequenced region showed little similarity with the proteins contained in the databases and were considered to be unknown proteins. (C) 1998 Elsevier Science B.V. All rights reserved.