Streptomyces coelicolor genes ftsL and divIC play a role in cell division but are dispensable for colony formation
Streptomyces coelicolor genes ftsL and divIC play a role in cell division but are dispensable for colony formation
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DOI：
10.1128/jb.01303-07
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发表时间：
2007-12-01
影响因子：
3.2
通讯作者：
McCormick, Joseph R.
中科院分区：
文献类型：
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作者：
Bennett, Jennifer A.;Aimino, Rachel M.;McCormick, Joseph R.
我们已经鉴定了革兰氏阳性菌丝体细菌天蓝色链霉菌A3中细菌细胞分裂基因ftsL和divIC的同源物（2）。我们通过缺失-插入突变表明，ftsL和divIC在S.天蓝色。当突变株生长在一个传统的丰富的培养基（R2 YE，含有高蔗糖），失活的ftsL或divIC导致形成气生菌丝部分收缩的分裂网站，但没有明确的分离的前孢子室。令人惊讶的是，这种表型在很大程度上抑制菌株生长在基本培养基或无蔗糖R2 YE，其中在许多气生菌丝的分裂位点已经完成收缩和孢子链是明显的。因此，渗透压似乎影响分裂缺陷的严重程度。此外，双突变株删除的ftsL和divIC是可行的，并具有类似于单突变株的培养基依赖性表型，这表明FtsL和DivIC执行的功能不是绝对需要的生长和孢子形成过程中的分隔。或者，另一种分裂蛋白可以部分补偿基本培养基或无蔗糖R2 YE上FtsL和DivIC的损失。最后，基于透射电子显微镜观察，我们提出，FtsL和DivIC参与协调对称环形向内生长的内陷隔膜。
We have characterized homologues of the bacterial cell division genes ftsL and divIC in the gram-positive mycelial bacterium Streptomyces coelicolor A3(2). We show by deletion-insertion mutations that ftsL and divIC are dispensable for growth and viability in S. coelicolor. When mutant strains were grown on a conventional rich medium (R2YE, containing high sucrose), inactivation of either ftsL or divIC resulted in the formation of aerial hyphae with partially constricted division sites but no clear separation of prespore compartments. Surprisingly, this phenotype was largely suppressed when strains were grown on minimal medium or sucrose-free R2YE, where division sites in many aerial hyphae had finished constricting and chains of spores were evident. Thus, osmolarity appears to affect the severity of the division defect. Furthermore, double mutant strains deleted for both ftsL and divIC are viable and have medium-dependent phenotypes similar to that of the single mutant strains, suggesting that functions performed by FtsL and DivIC are not absolutely required for septation during growth and sporulation. Alternatively, another division protein may partially compensate for the loss of both FtsL and DivIC on minimal medium or sucrose-free R2YE. Finally, based on transmission electron microscopy observations, we propose that FtsL and DivIC are involved in coordinating symmetrical annular ingrowth of the invaginating septum.