Gockel G, Hachtel W
Botanisches Institut der Universität Bonn, Germany.
Protist. 2000 Dec;151(4):347-51. doi: 10.1078/S1434-4610(04)70033-4.
Astasia longa is a colourless heterotrophic flagellate closely related to the photoautotrophic Euglena gracilis. A circular 73 kb plastid DNA (ptDNA) has been isolated from A. longa that is about half the size of the chloroplast DNA of E. gracilis (143 kb). We have determined the complete sequence of the ptDNA of A. longa and established a complete gene map. All chloroplast genes for photosynthesis-related proteins are completely absent from the A. longa plastid DNA except for rbcL, the gene for the ribulose-1,5-bisphosphate carboxylase large subunit. Identified genes encode components of the plastid transcriptional and translational machinery: genes for three subunits of a chloroplast RNA polymerase, 20 chloroplast ribosomal protein genes, a gene for a plastid elongation factor Tu, 27 plastidic tRNA genes and three tandemly arranged repeats of 16S, 23S and 5S rDNA. Transcripts of a number of genes were detected by Northern hybridisation. The ribulose-1,5-bisphosphate carboxylase large subunit protein has been identified by immunoblotting.
长裸藻是一种无色异养鞭毛虫，与光合自养的纤细裸藻亲缘关系密切。已从长裸藻中分离出一个环状的73 kb质体DNA（ptDNA），其大小约为纤细裸藻叶绿体DNA（143 kb）的一半。我们已确定了长裸藻ptDNA的完整序列并构建了完整的基因图谱。除了1,5-二磷酸核酮糖羧化酶大亚基基因rbcL外，长裸藻质体DNA中完全没有所有与光合作用相关蛋白的叶绿体基因。已鉴定的基因编码质体转录和翻译机制的组成部分：叶绿体RNA聚合酶三个亚基的基因、20个叶绿体核糖体蛋白基因、一个质体延伸因子Tu基因、27个质体tRNA基因以及16S、23S和5S rDNA的三个串联重复序列。通过Northern杂交检测到了许多基因的转录本。通过免疫印迹鉴定了1,5-二磷酸核酮糖羧化酶大亚基蛋白。
