从恶性疟原虫类质体样DNA转录的转运RNA基因。

Preiser P, Williamson D H, Wilson R J

Division of Parasitology, National Institute for Medical Research, Mill Hill, London, UK.

Nucleic Acids Res. 1995 Nov 11;23(21):4329-36. doi: 10.1093/nar/23.21.4329.

Besides their mitochondrial genome, malarial parasites contain a second organellar DNA. This 35 kb circular molecule has a number of features reminiscent of plastid DNAs. Sequence analysis shows that along with other genes the circle codes for 25 different tRNAs all of which are transcribed. Six of the tRNAs have some unusual features, and one has an intron, the only one found so far on the circle. Comparison of codon and anticodon usage indicates that the 25 tRNAs are sufficient to decode all the protein genes present on the circle. The maintenance of such a parsimonious but complete translation system is further evidence for the functionality of the circle.

除了线粒体基因组外，疟原虫还含有第二种细胞器DNA。这个35kb的环状分子具有许多类似于质体DNA的特征。序列分析表明，除其他基因外，该环状物编码25种不同的tRNA，所有这些tRNA都被转录。其中6种tRNA具有一些不寻常的特征，还有一种带有内含子，这是迄今为止在该环状物上发现的唯一内含子。密码子和反密码子使用情况的比较表明，这25种tRNA足以解码该环状物上存在的所有蛋白质基因。维持这样一个简约但完整的翻译系统进一步证明了该环状物的功能性。