Tanaka K, Oikawa K, Ohta N, Kuroiwa H, Kuroiwa T, Takahashi H
Institute of Molecular and Cellular Biosciences, University of Tokyo, Japan.
Science. 1996 Jun 28;272(5270):1932-5. doi: 10.1126/science.272.5270.1932.
A chloroplast RNA polymerase sigma factor is encoded by a nuclear gene, sigA, in the red alga Cyanidium caldarium RK-1. The encoded protein functions as an RNA polymerase sigma factor in vitro and it is localized to the chloroplast in vivo. SigA shows high sequence similarity to the sigma factors of cyanobacteria, which is indicative of the ancestral endosymbiotic event and subsequent transfer of the sigA gene to the nuclear genome.
叶绿体RNA聚合酶σ因子由红藻嗜热栖热放线菌RK-1中的一个核基因sigA编码。编码的蛋白质在体外作为RNA聚合酶σ因子发挥作用，并且在体内定位于叶绿体。SigA与蓝细菌的σ因子具有高度的序列相似性，这表明了原始的内共生事件以及随后sigA基因向核基因组的转移。
