MOLECULAR, FUNCTIONAL, AND EVOLUTIONARY ANALYSIS OF SEQUENCES SPECIFIC TO SALMONELLA
MOLECULAR, FUNCTIONAL, AND EVOLUTIONARY ANALYSIS OF SEQUENCES SPECIFIC TO SALMONELLA
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DOI：
10.1073/pnas.90.3.1033
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发表时间：
1993-02-01
影响因子：
11.1
通讯作者：
OCHMAN, H
中科院分区：
文献类型：
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作者：
GROISMAN, EA;STURMOSKI, MA;OCHMAN, H
由于沙门氏菌与一系列前所未有的疾病有关，因此发现对该物种特异性的序列通常被认为与其他肠道细菌中未发现的毒力属性有关。为了确定区分细菌物种的分子，遗传和表型特征，我们分析了最初被描述为仅限于沙门氏菌的五个克隆DNA片段。这些片段中的大多数映射到鼠伤寒沙门氏菌染色体上的独特位置，指示独立的进化事件，其中三个片段的G+C含量远低于沙门氏菌基因组，表明它们是通过水平转移产生的。确定显示非典型碱基组成的克隆之一的核苷酸序列。这个4.9 kb的片段含有一个开放的阅读框，与转录调节因子的LysR家族具有结构相似性。测试在该区域中具有缺失的菌株的>120个表型特征，包括对环境调节的lac基因融合体的集合的影响。此外，当在小鼠中测试毒力时，所有缺失菌株的表现与野生型亲本相似。
In that salmonellae have been implicated in an unprecedented array of diseases, sequences found to be specific to this species are often thought to be involved in the virulence attributes not seen in other enteric bacteria. To identify the molecular, genetic, and phenotypic characteristics that differentiate bacterial species, we analyzed five cloned DNA fragments that were originally described as being confined to Salmonella. Most of these segments mapped to unique positions on the Salmonella typhimurium chromosome indicative of independent evolutionary events, and three had G+C contents considerably lower than that of the Salmonella genome, suggesting that they arose through horizontal transfer. The nucleotide sequence was determined for one of the clones exhibiting an atypical base composition. This 4.9-kb fragment contained an open reading frame with structural similarity to the LysR family of transcriptional regulators. Strains harboring deletions in this region were tested for >120 phenotypic characteristics including the effects on a collection of environmentally regulated lac gene fusions. In addition, all deletion strains behaved like the wild-type parent when tested for virulence in mice.