Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA.
Science. 2010 Mar 5;327(5970):1258-61. doi: 10.1126/science.1186090.
Cyanobacterial carbon fixation is a major component of the global carbon cycle. This process requires the carboxysome, an organelle-like proteinaceous microcompartment that sequesters the enzymes of carbon fixation from the cytoplasm. Here, fluorescently tagged carboxysomes were found to be spatially ordered in a linear fashion. As a consequence, cells undergoing division evenly segregated carboxysomes in a nonrandom process. Mutation of the cytoskeletal protein ParA specifically disrupted carboxysome order, promoted random carboxysome segregation during cell division, and impaired carbon fixation after disparate partitioning. Thus, cyanobacteria use the cytoskeleton to control the spatial arrangement of carboxysomes and to optimize the metabolic process of carbon fixation.
蓝藻的碳固定是全球碳循环的主要组成部分。这个过程需要羧基体，一种类似细胞器的蛋白质微隔间，将碳固定酶与细胞质隔离开来。在这里，荧光标记的羧基体以线性方式进行空间排列。因此，正在分裂的细胞以非随机的方式均匀地分割羧基体。细胞骨架蛋白 ParA 的突变特别破坏了羧基体的有序性，促进了细胞分裂过程中羧基体的随机分离，并在不同的分隔后损害了碳固定。因此，蓝藻利用细胞骨架来控制羧基体的空间排列，并优化碳固定的代谢过程。
