Transformation is a widespread mechanism of horizontal gene transfer in bacteria. DNA uptake to the periplasmic compartment requires a DNA-uptake pilus and the DNA-binding protein ComEA. In the gram-negative bacteria, DNA is first pulled toward the outer membrane by retraction of the pilus and then taken up by binding to periplasmic ComEA, acting as a Brownian ratchet to prevent backward diffusion. A similar mechanism probably operates in the gram-positive bacteria as well, but these systems have been less well characterized. Transport, defined as movement of a single strand of transforming DNA to the cytosol, requires the channel protein ComEC. Although less is understood about this process, it may be driven by proton symport. In this review we also describe various phenomena that are coordinated with the expression of competence for transformation, such as fratricide, the kin-discriminatory killing of neighboring cells, and competence-mediated growth arrest.

中文翻译：

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天然感受态细菌摄取 DNA 的机制。

转化是细菌中水平基因转移的一种广泛机制。DNA 摄取到周质隔室需要 DNA 摄取菌毛和 DNA 结合蛋白 ComEA。在革兰氏阴性细菌中，DNA 首先通过菌毛的收缩被拉向外膜，然后通过与周质 ComEA 结合而被吸收，充当布朗棘轮以防止向后扩散。类似的机制可能也在革兰氏阳性细菌中起作用，但这些系统的特征还不太清楚。运输，定义为单链转化 DNA 向胞质溶胶的移动，需要通道蛋白 ComEC。尽管对该过程的了解较少，但它可能是由质子同步驱动的。