Siemeister G, Buchholz C, Hachtel W
Botanisches Institut, Universität Bonn, Federal Republic of Germany.
Mol Gen Genet. 1990 Feb;220(3):425-32. doi: 10.1007/BF00391749.
The nucleotide sequence of a 6156 bp segment of the circular 73 kb DNA from Astasia longa resembling the chloroplast DNA of Euglena was determined. The genes for the plastid elongation factor Tu (tufA) and the ribosomal protein S7 (rps7), six tRNA genes (trnQ, trnS, trnG, trnM, trnT, trnR), and three open reading frames were identified. These genes show a high degree of sequence similarity (73%-99%) to the corresponding genes on the Euglena chloroplast genome. The tufA gene contains two small AT-rich introns within its coding region. Northern analysis revealed the in vivo transcription of the tufA gene and of a reading frame of 456 codons into monocistronic mRNAs of 1.3 and 1.4 kb, respectively. The arrangement and organization of the genes on the 73 kb DNA of the colourless heterotrophic flagellate Astasia and the chloroplast DNA of autotrophic Euglena are compared.
测定了来自长眼虫（Astasia longa）的环状73 kb DNA中一段6156 bp片段的核苷酸序列，该片段类似于眼虫（Euglena）的叶绿体DNA。鉴定出了质体延伸因子Tu（tufA）和核糖体蛋白S7（rps7）的基因、六个tRNA基因（trnQ、trnS、trnG、trnM、trnT、trnR）以及三个开放阅读框。这些基因与眼虫叶绿体基因组上的相应基因显示出高度的序列相似性（73%-99%）。tufA基因在其编码区内含有两个小的富含AT的内含子。Northern分析揭示了tufA基因和一个456个密码子的阅读框分别转录为1.3 kb和1.4 kb的单顺反子mRNA。比较了无色异养鞭毛虫长眼虫73 kb DNA上的基因排列和组织与自养眼虫叶绿体DNA的情况。
