Koyama Yosuke, Takimoto Koji, Kojima Asuka, Asai Kei, Matsuoka Satoshi, Mitsui Toshiaki, Matsumoto Kouji, Hara Hiroshi, Ohta Niji
Department of Biochemistry and Molecular Biology, Graduate School of Science and Engineering, Saitama University, Saitama, Japan.
Biosci Biotechnol Biochem. 2011;75(10):2073-8. doi: 10.1271/bbb.110338. Epub 2011 Oct 7.
SecA is an ATP-driven motor for protein translocation in bacteria and plants. Mycobacteria and listeria were recently found to possess two functionally distinct secA genes. In this study, we found that Cyanidioschyzon merolae, a unicellular red alga, possessed two distinct secA-homologous genes; one encoded in the cell nucleus and the other in the plastid genome. We found that the plastid-encoded SecA homolog showed significant ATPase activity at low temperature, and that the ATPase activity of the nuclear-encoded SecA homolog showed significant activity at high temperature. We propose that the two SecA homologs play different roles in protein translocation.
SecA是一种由ATP驱动的用于细菌和植物中蛋白质转运的分子马达。最近发现分枝杆菌和李斯特菌拥有两个功能不同的secA基因。在本研究中，我们发现单细胞红藻梅洛拉蓝细菌（Cyanidioschyzon merolae）拥有两个不同的secA同源基因；一个编码于细胞核中，另一个编码于质体基因组中。我们发现质体编码的SecA同源物在低温下表现出显著的ATP酶活性，而核编码的SecA同源物的ATP酶活性在高温下表现出显著活性。我们提出这两个SecA同源物在蛋白质转运中发挥不同作用。
