Laboratoire de Virologie, Institut de Biologie Moléculaire et Cellulaire du C.N.R.S., 15 rue Descartes, 67084, Strasbourg Cédex, France.
Plant Mol Biol. 1986 Jul;7(4):301-9. doi: 10.1007/BF00752902.
InNicotiana sylvestris only four transcripts coding for the small subunit of RUBISCO are present in leaves. They are very closely related as they are identical in the nucleotide sequence of the non-coding regions and show only three silent point differences in the region coding for the mature peptide.The main difference among these four transcripts lies in the length of the non-coding regions. Half of the SmRNA population as confirmed by direct RNA sequencing has an additional nucleotide sequence in the leader region. Two cDNAs have an additional nucleotide sequence at the end of the 3' non-coding region. Based on these criteria the transcripts were classified into two groups:.group I has a 73-nucleotide-long leader sequence and the nucleotides T, A and C at position 327, 432 and 519 in the coding region..group II has a 60-nucleotide-long leader sequence and the nucleotides C, G and T at these positions in the coding region.The two cDNAs showing a difference in the length of the 3' non-coding region belong to group II.The study of all these transcripts argues for the possibility that only two families of genes are expressed in leaves ofN. sylvestris.
在普通烟草中，仅有 4 种编码 Rubisco 小亚基的转录本存在于叶片中。它们非常相似，因为非编码区的核苷酸序列完全相同，且在编码成熟肽的区域仅存在 3 个同义突变。这 4 种转录本的主要区别在于非编码区的长度。直接 RNA 测序证实，SmRNA 群体的一半在其 5'非编码区具有额外的核苷酸序列。2 个 cDNA 在 3'非编码区的末端具有额外的核苷酸序列。基于这些标准，将转录本分为 2 组：I 组具有 73 个核苷酸长的 5'非编码区，以及在编码区的位置 327、432 和 519 处具有 T、A 和 C 核苷酸；II 组具有 60 个核苷酸长的 5'非编码区，以及在编码区的这些位置处具有 C、G 和 T 核苷酸。在 3'非编码区长度上存在差异的两个 cDNA 属于 II 组。对所有这些转录本的研究表明，普通烟草叶片中仅表达 2 个家族的基因。
