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首页> 外文期刊>Journal of bacteriology >Mutations which alter the kinetics of calcium transport alter the regulation of competence in Streptococcus pneumoniae.
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Mutations which alter the kinetics of calcium transport alter the regulation of competence in Streptococcus pneumoniae.

机译：改变钙转运动力学的突变会改变肺炎链球菌的能力调节。

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In Streptococcus pneumoniae, Ca2+ induces a stress response which is regulated by a proteic activator known as competence factor (CF). This stress response is expressed as the induction of competence for DNA uptake and genetic transformation in exponentially growing cultures and by autolysis in late exponential phase. DNA transport during competence can be described as a homeostatic response that prevents autolysis of the cultures. Electrogenic and cooperative calcium transport with a Hill number (nH) of 2 appears to mediate this Ca2+ response. Mutant strains altered in their kinetics for Ca2+ transport, with nHs of 1 and 4, were isolated and characterized in order to address the role of the kinetics of Ca2+ transport in the Ca2+ response. The reduced cooperativity of Ca2+ uptake in mutant strain Cp2200 was associated with an absolute requirement for added CF to develop competence and with resistance to autolysis. The enhanced cooperativity of Ca2+ uptake in mutant strain Cp3300 was associated with facilitated competence and hypersensitivity to autolysis. Moreover, the mutation carried by strain Cp3300 increases the CF response of previously described competence-defective mutants. The pleiotropic mutants Cp2200 and Cp3300 allowed us to demonstrate that cooperativity of transport determines the Ca2+ response in S. pneumoniae.
机译：在肺炎链球菌中，Ca2 +诱导了一种应激反应，该应激反应由一种被称为能力因子（CF）的蛋白质活化剂调节。这种应激反应表示为指数生长培养物中DNA摄取和遗传转化能力的诱导，以及指数后期的自溶作用。能力中的DNA转运可描述为阻止培养物自溶的体内稳态反应。希尔数（nH）为2的电生和协同钙转运似乎介导了这种Ca2 +反应。分离并表征了其Ca2 +传输动力学改变的突变株，nHs为1和4，以解决Ca2 +传输动力学在Ca2 +反应中的作用。突变菌株Cp2200中Ca2 +吸收的降低的协同作用与添加CF形成能力和抗自溶性的绝对要求有关。突变菌株Cp3300中Ca2 +吸收的协同作用增强与自溶能力和超敏性有关。而且，由菌株Cp3300携带的突变增加了先前描述的能力缺陷突变体的CF响应。多效性突变体Cp2200和Cp3300使我们证明转运的协同作用决定了肺炎链球菌的Ca2 +响应。

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