The sporulating, filamentous soil bacterium Streptomyces venezuelae ATCC 10712 differentiates under submerged and surface growth conditions. In order to lay a solid foundation for the study of development-associated division for this organism, a congenic set of mutants was isolated, individually deleted for a gene encoding either a cytoplasmic (i.e. ftsZ) or core inner membrane (i.e. divIC, ftsL, ftsI, ftsQ, ftsW) component of the divisome. While ftsZ mutants are completely blocked for division, single mutants in the other core divisome genes resulted in partial, yet similar, blocks in sporulation septum formation. Double and triple mutants for core divisome membrane components displayed phenotypes that were similar to those of the single mutants, demonstrating that the phenotypes were not synergistic. Division in this organism is still partially functional without multiple core divisome proteins, suggesting that perhaps other unknown lineage-specific proteins perform redundant functions. In addition, by isolating an ftsZ2p mutant with an altered -10 region, the conserved developmentally controlled promoter was also shown to be required for sporulation-associated division. Finally, microscopic observation of FtsZ-YFP dynamics in the different mutant backgrounds led to the conclusion that the initial assembly of regular Z rings does not per se require the tested divisome membrane proteins, but the stability of Z rings is dependent on the divisome membrane components tested. The observation is consistent with the interpretation that Z ring instability likely results from and further contributes to the observed defects in sporulation septation in mutants lacking core divisome proteins.

中文翻译：

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核心分裂蛋白对委内瑞拉链霉菌 ATCC 10712 细胞分裂的影响

产孢子的丝状土壤细菌 Streptomyces venezuelae ATCC 10712 在水下和表面生长条件下分化。为了为研究该生物的发育相关分裂奠定坚实的基础，分离了一组同类突变体，单独删除了编码细胞质（即 ftsZ）或核心内膜（即 divIC、ftsL、 ftsI, ftsQ, ftsW) 分体的分量。虽然 ftsZ 突变体完全阻止分裂，但其他核心分裂基因中的单个突变体导致部分但相似的孢子形成隔膜形成阻止。双和核心divisome膜元件三重突变体显示的是相似的那些单突变体的，这表明表型不是协同的表型。在没有多个核心分裂蛋白的情况下，该生物体中的分裂仍然部分功能，这表明可能其他未知的谱系特异性蛋白质执行冗余功能。此外，通过分离具有改变的 -10 区域的 ftsZ2p 突变体，还表明保守的发育控制启动子是孢子形成相关分裂所必需的。最后，对不同突变体背景下 FtsZ-YFP 动力学的微观观察得出结论，规则 Z 环的初始组装本身不需要测试的二分体膜蛋白，但 Z 环的稳定性取决于二分体膜成分测试。