SpoVID guides SafA to the spore coat in Bacillus subtilis
SpoVID guides SafA to the spore coat in Bacillus subtilis
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DOI：
10.1128/jb.183.10.3041-3049.2001
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发表时间：
2001-05-01
影响因子：
3.2
通讯作者：
Moran, CP
中科院分区：
文献类型：
--
作者：
Ozin, AJ;Samford, CS;Moran, CP
细菌通过将蛋白质定位到特定的亚细胞位置来组装复杂的结构。包裹枯草芽孢杆菌孢子的蛋白质外壳就是一个需要协调靶向和组装超过 24 个多肽的结构的例子。外壳组装的最早阶段需要三种形态发生蛋白的作用：SpoIVA、CotE 和 SpoVID。在第一步中，SpoIVA 的基底层在前孢子表面周围形成，指导 CotE 蛋白环随后定位在距前孢子表面约 75 nm 的位置。 SpoVID 位于前孢子膜附近，其功能是维持 CotE 环的完整性并将新生外壳固定到下面的孢子结构上。然而，尚不清楚哪些孢子外壳蛋白直接与 SpoVID 相互作用。在本研究中，我们使用酵母双杂交系统在体内和体外检查了 SpoVID 与另一种孢子外壳蛋白 SafA 之间的相互作用。我们发现了 SpoVID 和 SafA 直接相互作用以及 SafA 与其自身相互作用的证据，免疫荧光显微镜显示 SafA 在外壳组装过程中早期定位在前孢子周围，并且 SafA 的这种定位依赖于 SpoVID。此外，SafA 靶向前孢子也依赖于 SpoIVA，正如 SpoVID 靶向前孢子一样。我们认为 SafA 定位到孢子衣需要与 SpoVID 直接相互作用。
Bacteria assemble complex structures by targeting proteins to specific subcellular locations. The protein coat that encases Bacillus subtilis spores is an example of a structure that requires coordinated targeting and assembly of more than 24 polypeptides. The earliest stages of coat assembly require the action of three morphogenetic proteins: SpoIVA, CotE, and SpoVID, In the first steps, a basement layer of SpoIVA forms around the surface of the forespore, guiding the subsequent positioning of a ring of CotE protein about 75 nm from the forespore surface. SpoVID localizes near the forespore membrane where it functions to maintain the integrity of the CotE ring and to anchor the nascent coat to the underlying spore structures. However, it is not known which spore coat proteins interact directly with SpoVID, In this study we examined the interaction between SpoVID and another spore coat protein, SafA in vivo using the yeast two-hybrid system and in vitro. We found evidence that SpoVID and SafA directly interact and that SafA interacts with itself, Immunofluorescence microscopy showed that SafA localized around the forespore early during coat assembly and that this localization of SafA was dependent on SpoVID. Moreover, targeting of SafA to the forespore was also dependent on SpoIVA, as was targeting of SpoVID to the forespore, We suggest that the localization of SafA to the spore coat requires direct interaction with SpoVID.