Área de Microbiología, Departamento de Biología Funcional, IUOPA and ISPA, Facultad de Medicina, Universidad de Oviedo, 33006 Oviedo, Spain.
Int J Mol Sci. 2022 Apr 30;23(9):4984. doi: 10.3390/ijms23094984.
DNA replication starts with the DnaA binding to the origin of replication. Differently to most bacteria, cytokinesis only occurs during sporulation. Cytokinesis is modulated by the divisome, an orderly succession of proteins initiated by FtsZ. Here, we characterised SCO2102, a protein harbouring a DnaA II protein-protein interaction domain highly conserved in . The knockout shows highly delayed sporulation. SCO2102-mCherry frequently co-localises with FtsZ-eGFP during sporulation and greatly reduces FtsZ-eGFP Z-ladder formation, suggesting a role of SCO2102 in sporulation. localises up-stream of , a methylenetetrahydrofolate reductase involved in methionine and dTMP synthesis. expression is highly regulated, involving two promoters and a conditional transcription terminator. The knockout shows reduced DNA synthesis and a non-sporulating phenotype. SCO2102-mCherry co-localises with SCO2103-eGFP during sporulation, and SCO2102 is essential for the SCO2103 positioning at sporulating hyphae, since SCO2103-eGFP fluorescent spots are absent in the knockout. We propose a model in which SCO2102 positions SCO2103 in sporulating hyphae, facilitating nucleotide biosynthesis for chromosomal replication. To the best of our knowledge, SCO2102 is the first protein harbouring a DnaA II domain specifically found during sporulation, whereas SCO2103 is the first methylenetetrahydrofolate reductase found to be essential for sporulation.
DNA 复制始于 DnaA 与复制起点的结合。与大多数细菌不同，细胞分裂仅发生在孢子形成过程中。细胞分裂由分隔体（divisome）调节，这是一个由 FtsZ 引发的有序蛋白质连续体。在这里，我们对 SCO2102 进行了特征描述，该蛋白含有 DnaA II 蛋白-蛋白相互作用结构域，在 中高度保守。 敲除株表现出明显延迟的孢子形成。SCO2102-mCherry 在孢子形成过程中经常与 FtsZ-eGFP 共定位，并大大减少 FtsZ-eGFP Z 梯形成，表明 SCO2102 在孢子形成中起作用。 定位于, 一种参与甲硫氨酸和 dTMP 合成的亚甲基四氢叶酸还原酶的上游。 表达受到高度调控，涉及两个启动子和一个条件转录终止子。 敲除株表现出减少的 DNA 合成和非孢子形成表型。SCO2102-mCherry 在孢子形成过程中与 SCO2103-eGFP 共定位，并且 SCO2102 对于 SCO2103 在孢子形成菌丝中的定位是必需的，因为在 敲除株中不存在 SCO2103-eGFP 荧光点。我们提出了一个模型，其中 SCO2102 定位 SCO2103 在孢子形成菌丝中，为染色体复制提供核苷酸生物合成。据我们所知，SCO2102 是第一个在孢子形成过程中特异性发现的含有 DnaA II 结构域的蛋白，而 SCO2103 是第一个发现对 孢子形成必不可少的亚甲基四氢叶酸还原酶。
