Michel Christian J, Seligmann Hervé
Equipe de Bioinformatique Théorique, ICube, Université de Strasbourg, CNRS, 300 Boulevard Sébastien Brant, 67400 Illkirch, France.
National Natural History Museum Collections, The Hebrew University of Jerusalem, 91904 Jerusalem, Israel; Department of Life Sciences, Ben Gurion University, 84105 Beer Sheva, Israel.
Biosystems. 2014 Apr;118:39-50. doi: 10.1016/j.biosystems.2014.02.002. Epub 2014 Feb 21.
The C(3) self-complementary circular code X identified in genes of prokaryotes and eukaryotes is a set of 20 trinucleotides enabling reading frame retrieval and maintenance, i.e. a framing code (Arquès and Michel, 1996; Michel, 2012, 2013). Some mitochondrial RNAs correspond to DNA sequences when RNA transcription systematically exchanges between nucleotides (Seligmann, 2013a,b). We study here the 23 bijective transformation codes ΠX of X which may code nucleotide exchanging RNA transcription as suggested by this mitochondrial observation. The 23 bijective transformation codes ΠX are C(3) trinucleotide circular codes, seven of them are also self-complementary. Furthermore, several correlations are observed between the Reading Frame Retrieval (RFR) probability of bijective transformation codes ΠX and the different biological properties of ΠX related to their numbers of RNAs in GenBank's EST database, their polymerization rate, their number of amino acids and the chirality of amino acids they code. Results suggest that the circular code X with the functions of reading frame retrieval and maintenance in regular RNA transcription, may also have, through its bijective transformation codes ΠX, the same functions in nucleotide exchanging RNA transcription. Associations with properties such as amino acid chirality suggest that the RFR of X and its bijective transformations molded the origins of the genetic code's machinery.
在原核生物和真核生物基因中发现的C(3)自互补循环码X是一组由20个三核苷酸组成的集合，能够实现读码框检索和维持，即一种成帧码（阿尔凯斯和米歇尔，1996年；米歇尔，2012年、2013年）。当RNA转录在核苷酸之间系统地交换时，一些线粒体RNA对应于DNA序列（塞利格曼，2013a、b）。我们在此研究X的23种双射变换码ΠX，它们可能如线粒体观察结果所暗示的那样编码核苷酸交换的RNA转录。这23种双射变换码ΠX是C(3)三核苷酸循环码，其中七种也是自互补的。此外，还观察到双射变换码ΠX的读码框检索（RFR）概率与ΠX在GenBank的EST数据库中的RNA数量、聚合速率、氨基酸数量以及它们编码的氨基酸手性等不同生物学特性之间存在若干相关性。结果表明，在常规RNA转录中具有读码框检索和维持功能的循环码X，通过其双射变换码ΠX，在核苷酸交换的RNA转录中可能也具有相同的功能。与氨基酸手性等特性的关联表明，X及其双射变换的RFR塑造了遗传密码机制的起源。
