Sharp Marc D, Pogliano Kit
Division of Biology, University of California, San Diego, La Jolla, CA 92093-0349, USA.
Science. 2002 Jan 4;295(5552):137-9. doi: 10.1126/science.1066274.
SpoIIIE mediates postseptational chromosome partitioning in Bacillus subtilis, but the mechanism controlling the direction of DNA transfer remains obscure. Here, we demonstrated that SpoIIIE acts as a DNA exporter: When SpoIIIE was synthesized in the larger of the two cells necessary for sporulation, the mother cell, DNA was translocated into the smaller forespore; however, when it was synthesized in the forespore, DNA was translocated into the mother cell. Furthermore, the DNA-tracking domain of SpoIIIE inhibited SpoIIIE complex assembly in the forespore. Thus, during sporulation, chromosome partitioning is controlled by the preferential assembly of SpoIIIE in one daughter cell.
SpoIIIE介导枯草芽孢杆菌中隔膜形成后的染色体分配,但控制DNA转移方向的机制仍不清楚。在这里,我们证明SpoIIIE作为一种DNA输出蛋白:当SpoIIIE在芽孢形成所需的两个细胞中较大的那个细胞即母细胞中合成时,DNA被转运到较小的前芽孢中;然而,当它在前芽孢中合成时,DNA被转运到母细胞中。此外,SpoIIIE的DNA追踪结构域抑制了前芽孢中SpoIIIE复合物的组装。因此,在芽孢形成过程中,染色体分配由SpoIIIE在一个子细胞中的优先组装控制。