Mechanisms of Transforming DNA Uptake to the Periplasm of Bacillus subtilis.
Mechanisms of Transforming DNA Uptake to the Periplasm of Bacillus subtilis.
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DOI：
10.1128/mbio.01061-21
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发表时间：
2021-06-29
期刊：
影响因子：
6.4
通讯作者：
Dubnau D
中科院分区：
文献类型：
--
作者：
Hahn J;DeSantis M;Dubnau D
我们在这里证明，收购的DNase抗性转化DNA，通常被认为是表明运输到细胞质，反映了摄取的周质，需要重新评估的结论转化中的几种蛋白质的作用。新的证据表明，转化菌毛是需要DNA结合到细胞两极附近的细胞表面和启动摄取。枯草芽孢杆菌的膜锚定ComEA的细胞分布在DNA摄取期间不显著改变，如弧菌和奈瑟氏球菌的未锚定ComEA。相反，我们的证据表明，ComEA稳定在周质中的局部区域的转化DNA的附着，然后介导摄取，可能是通过布朗棘轮机制。之后，DNA被转移到通道蛋白ComEC的周质部分，其在摄取到周质中起着先前未被怀疑的作用。我们表明，转化核酸内切酶NucA也有利于摄取的周质和以前证明的作用，ComFA在收购的DNase抗性来自不稳定的ComGA时，ComFA被删除。这些结果促使人们对转化的DNA摄取的早期阶段有了新的认识。
We demonstrate here that the acquisition of DNase resistance by transforming DNA, often assumed to indicate transport to the cytoplasm, reflects uptake to the periplasm, requiring a reevaluation of conclusions about the roles of several proteins in transformation. The new evidence suggests that the transformation pilus is needed for DNA binding to the cell surface near the cell poles and for the initiation of uptake. The cellular distribution of the membrane-anchored ComEA of Bacillus subtilis does not dramatically change during DNA uptake as does the unanchored ComEA of Vibrio and Neisseria. Instead, our evidence suggests that ComEA stabilizes the attachment of transforming DNA at localized regions in the periplasm and then mediates uptake, probably by a Brownian ratchet mechanism. Following that, the DNA is transferred to periplasmic portions of the channel protein ComEC, which plays a previously unsuspected role in uptake to the periplasm. We show that the transformation endonuclease NucA also facilitates uptake to the periplasm and that the previously demonstrated role of ComFA in the acquisition of DNase resistance derives from the instability of ComGA when ComFA is deleted. These results prompt a new understanding of the early stages of DNA uptake for transformation.