Novel regulatory mutants of the phosphate regulon in Escherichia coli K-12.
Novel regulatory mutants of the phosphate regulon in Escherichia coli K-12.
复制标题
大肠杆菌 K-12 中磷酸调节子的新型调节突变体。
DOI：
10.1016/0022-2836(86)90421-3
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发表时间：
1986
影响因子：
5.6
通讯作者：
Wanner,BL
中科院分区：
文献类型：
--
作者：
Wanner,BL
新的多效性突变体被分离出来，表达phoA，psiEorpsiO启动子组成型，同时改变细菌碱性磷酸酶调节，碳利用或紫外线敏感性。为此，从具有适当lacZ转录融合的菌株中分离Lac+突变体。超过300个独立的突变体进行了表征，所有的组成型表达phoAmap inphoR，phoU，磷酸盐特异性运输系统或一个新的位点称为phoF。然而，只有lyphoU突变体同时表达phoA和psiE。利用碳水化合物的突变体，显示组成型表达psiE和psiOmap incya，crp和可能的crr。此外，许多紫外线敏感的突变体被发现，显示增加psiO表达和地图inlon。其他一些导致组成性psiO表达的突变（通常由磷酸盐、氮或碳饥饿或缺氧诱导）显示phoA表达降低。此外，还发现了几个突变体，它们显示出影响psiOorphoA转录的不寻常的亚稳特性。在这些情况下，菌落自发地在诱导和抑制的“状态”之间切换，这与细菌碱性磷酸酶的表达有关。在某些情况下，乳糖表型或细菌碱性磷酸酶合成的克隆变异是recA独立的，并且表型类似于鼠伤寒沙门氏菌的相变异。后一类被称为“相位突变体”。突变体的蛋白质-核酸相互作用和/或可能的变化，即修饰或重排，在磷酸盐基因系统，这是生理调节的方面进行了讨论。
New pleiotropic mutants were isolated that express either thephoA,psiEorpsiOpromoter constitutively and simultaneously alter bacterial alkaline phosphatase regulation, carbon utilization or ultraviolet light sensitivity. To do this, Lac+mutants were isolated from strains with the appropriatelacZtranscriptional fusions. Over 300 independent mutants were characterized, and all that constitutively expressphoAmap inphoR,phoU, the phosphate-specific transport system or a new locus calledphoF. However, onlyphoUmutants express bothphoAandpsiEconstitutively. Carbohydrate-utilizing mutants that show constitutive expression ofpsiEandpsiOmap incya,crpand, possibly,crr. Also, numerous ultraviolet-light-sensitive mutants were discovered that show increasedpsiOexpression and map inlon. Some other mutations that lead to constitutivepsiOexpression (which is normally induced either by phosphate, nitrogen or carbon starvation or anoxia) show decreased expression ofphoA. Also, several mutants were found that show an unusual metastable character affectingpsiOorphoAtranscription. In these, colonies spontaneously switch between an induced and repressed “state” with respect tolacor bacterial alkaline phosphatase expression. In some, the clonal variation of the lactose phenotype or bacterial alkaline phosphatase synthesis isrecA-independent and phenotypically resembles phase variation inSalmonella typhimurium. The latter class are called “phase mutants”. The mutants are discussed in terms of protein-nucleic acid interactions and/or possible changes in the DNA, i.e. modifications or rearrangements, within the phosphate gene system, that are physiologically regulated.