Effects of rodA and pbp2b Disruption on Cell Morphology and Oxidative Stress Response of Streptococcus thermophilus CNRZ368
Effects of rodA and pbp2b Disruption on Cell Morphology and Oxidative Stress Response of Streptococcus thermophilus CNRZ368
复制标题
rodA 和 pbp2b 破坏对嗜热链球菌 CNRZ368 细胞形态和氧化应激反应的影响
作者：
Annabelle Thibessard;Annabelle Fernandez;B. Gintz;N. Leblond;B. Decaris
摘要利用插入突变技术从嗜热链球菌CNRZ 368中分离出耐氧化应激能力被修饰的克隆。在此过程中，发现两个甲萘醌敏感克隆（6G4和18C3）显示异常的细胞形态和扭曲的链拓扑结构，并进行了进一步研究。6G4和18 C3突变体的分子特征表明，它们分别在与rodA和pbp2b同源的开放阅读框中被破坏。这两种基因编码的蛋白质在大肠杆菌中被描述为涉及在细胞伸长过程中的肽聚糖合成，并在确定细胞的杆状的功能。这项工作报告了肽聚糖的生物合成和氧化应激防御之间的可能联系。嗜热菌CNRZ 368。
ABSTRACT Insertional mutagenesis was used to isolate clones from Streptococcus thermophilus CNRZ368 that were modified in their abilities to tolerate oxidative stress. During this process, two menadione-sensitive clones (6G4 and 18C3) were found to display abnormal cell morphologies and distorted chain topologies and were further studied. Molecular characterization of both 6G4 and 18C3 mutants indicated that they were disrupted in open reading frames homologous to rodA and pbp2b, respectively. Both genes encoded proteins in Escherichia coli that were described as being implicated in peptidoglycan synthesis during the process of cell elongation and to function in determining the rod shape of the cell. This work reports a possible connection between peptidoglycan biosynthesis and oxidative stress defense in S. thermophilus CNRZ368.