| Combining Gel Retardation and Footprinting to Determine Protein-DNA Interactions of Specific and/or Less Stable Complexes
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Author:
Date:
2020-12-05
[Abstract] DNA footprinting is a classic technique to investigate protein-DNA interactions. However, traditional footprinting protocols can be unsuccessful or difficult to interpret if the binding of the protein to the DNA is weak, the protein has a fast off-rate, or if several different protein-DNA complexes are formed. Our protocol differs from traditional footprinting protocols, because it provides a method to isolate the protein-DNA complex from a native gel after treatment with the footprinting agent, thus removing the bound DNA from the free DNA or other protein-DNA complexes. The DNA is then extracted from the isolated complex before electrophoresis on a sequencing gel to determine the footprinting pattern. This analysis provides a possible solution for those who have been unable to use ...
[摘要] [摘要] DNA足迹是研究蛋白质-DNA相互作用的经典技术。但是，如果蛋白质与DNA的结合较弱，蛋白质的脱落速率较快，或者形成了几种不同的蛋白质-DNA复合物，则传统的足迹方案可能会失败或难以解释。我们的协议不同于传统的足迹协议，因为它提供了一种在使用足迹剂处理后从天然凝胶中分离蛋白质-DNA复合物的方法，从而从游离DNA或其他蛋白质-DNA复合物中去除了结合的DNA。然后从分离的复合物中提取DNA，然后在测序凝胶上电泳以确定印迹模式。该分析为无法使用传统足迹法确定蛋白质与DNA接触的人提供了可能的解决方案。
[背景]核酸酶/化学足迹是一个典型的方法来探测蛋白质-DNA相互作用（腊士和施米茨，1978;萨瑟-德怀特和Gralla，1989;汉普等人，2007） ...
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| Induction of Natural Competence in Genetically-modified Lactococcus lactis
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Author:
Date:
2018-07-05
[Abstract] Natural competence can be activated in Lactoccocus lactis subsp lactis and cremoris upon overexpression of ComX, a master regulator of bacterial competence. Herein, we demonstrate a method to activate bacterial competence by regulating the expression of the comX gene by using a nisin-inducible promoter in an L. lactis strain harboring either a chromosomal or plasmid-encoded copy of nisRK. Addition of moderate concentrations of the inducer nisin resulted in concomitant moderate levels of ComX, which led to an optimal transformation rate (1.0 x 10-6 transformants/total cell number/g plasmid DNA). Here, a detailed description of the optimized protocol for competence induction is presented.
[摘要] 在过度表达细菌能力的主要调节因子ComX后，天然能力可以在乳酸乳球菌亚种乳酸和 cremoris 中激活。 在本文中，我们展示了通过在 L中使用乳链菌肽诱导型启动子调节 comX 基因的表达来激活细菌能力的方法。 含有 nisRK 的染色体或质粒编码拷贝的lactis 菌株。 加入中等浓度的诱导剂乳链菌肽导致伴随的中等水平的ComX，其导致最佳转化率（1.0×10 2 sup / -6>转化子/总细胞数/ g质粒DNA）。 在此，提出了用于能力归纳的优化协议的详细描述。
【背景】自然能力是细菌通过专门的摄取机制获得外源DNA的过程，之后内化的DNA整合到其基因组中或作为质粒DNA维持。一些细菌在特定的环境触发因素如基因毒性应激或饥饿时进入能力状态（Seitz和Blokesch，2013; Blokesch，2016）。群体感应系统，如 comCDE 或 comRS ，控制着革兰氏阳性菌的自然能力的激活（Håvarstein et al。，1995; Pestova et al。，1996; Kleerebezem et al。，1997b; Fontaine et al。，2015）。更具体地说， comC 和 comS 编码信息素，而 comD 编码组氨酸激酶和 comE 和 comR 编码响应调节器（Håvarstein et al。，1995; ...
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| RNA Isolation from Synechocystis
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Author:
Date:
2015-03-20
[Abstract] The protocol describes the procedure of total RNA isolation from cells of the cyanobacterium Synechocystis sp. PCC 6803. This protocol is also applicable to Synechococcus elongatus PCC 7942 and PCC 6301, Thermosynechococcus vulcanus, and other unicellular and filamentous species of cyanobacteria that do not have thick polysaccharide-containing outer layers. For the latter, Trizol-containing protocols should be adapted. The yield of RNA depends on optical density of cyanobacterial culture and may reach up to 10-20 µg of total RNA per 1 ml of cell culture. RNA isolated by this method can be used for Northern blot hybridization, RT-qPCR, microarrays and Next Generation Sequencing.
[摘要] 该方案描述了从蓝细菌集胞藻的细胞总RNA分离的程序。 PCC 6803。该方案也适用于细长聚球藻PCC 7942和PCC 6301，硫酸高热杆菌（Thermosynechococcus vulcanus）和其它单细胞和丝状物种的蓝细菌，其不具有含多糖的 外层。 对于后者，应该修改含有Trizol的协议。 RNA的产量取决于蓝细菌培养物的光密度，并且可以达到每1ml细胞培养物高达10-20μg的总RNA。 通过该方法分离的RNA可用于Northern印迹杂交，RT-qPCR，微阵列和下一代测序。
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