Koike H, Shibata M, Yasutomi K, Kashino Y, Satoh K
Department of Life Science, Faculty of Science, Himeji Institute of Technology, Harima Science Garden City, Hyogo, 678-1297, Japan,
Photosynth Res. 2000;65(3):207-17. doi: 10.1023/A:1010734912776.
Thylakoid membranes and Photosystem I (PS I) complexes were isolated from a glaucocystophyte, Cyanophora paradoxa, which is thought to have the most primitive 'plastids', and the proteins related to PS I were examined. The intrinsic light-harvesting chlorophyll protein complexes of PS I (LHC I) were not detected by an immunological method. The PS I complexes consisted of at least eight low-molecular-mass proteins in addition to PS I reaction center proteins. The N-terminal sequence of the PsaD protein has higher homology to that of Chlamydomonas reinhardtii and land plants, than to that of other algae or cyanobacteria. On the other hand, the PsaL sequence has the highest homology to those of cyanobacteria. Taking into account the other sequences of PS I components whose genes are encoded in the cyanelle genome, and the fact that LHC I is not detected, it is concluded that PS I of C. paradoxa has chimeric characteristics of both 'green' lineages and cyanobacteria.
从一种被认为具有最原始“质体”的蓝隐藻（Cyanophora paradoxa）中分离出类囊体膜和光系统I（PS I）复合体，并对与PS I相关的蛋白质进行了研究。通过免疫方法未检测到PS I的内在捕光叶绿素蛋白复合体（LHC I）。PS I复合体除了PS I反应中心蛋白外，还至少由八种低分子量蛋白质组成。PsaD蛋白的N端序列与莱茵衣藻和陆地植物的同源性高于与其他藻类或蓝细菌的同源性。另一方面，PsaL序列与蓝细菌的同源性最高。考虑到PS I组分的其他序列（其基因在蓝小体基因组中编码）以及未检测到LHC I这一事实，可以得出结论，蓝隐藻的PS I具有“绿色”谱系和蓝细菌的嵌合特征。
