Reiss T, Link G
Eur J Biochem. 1985 Apr 15;148(2):207-12. doi: 10.1111/j.1432-1033.1985.tb08826.x.
DNA-protein complexes that are capable of RNA synthesis in vitro (transcriptionally active chromosomes) were isolated from both chloroplasts and etioplasts of mustard (Sinapis alba L.) seedlings. Analyses of the polypeptide pattern of these complexes indicate that they comprise a specific subset of plastid proteins, distinct from the overall pattern of either the soluble or membrane-bound plastic proteins. DNA-protein complexes from the two plastid types have polypeptides in common. However, at least several polypeptides are highly enriched in either the chloroplast or the etioplast DNA-protein complex. The EcoRI restriction endonuclease fragments of the DNA associated with the complexes from either plastid type are the same. They are identical with the fragments obtained from highly purified chloroplast DNA. The transcriptional activity of the chloroplast complex is more than ten times higher than the activity of the etioplast complex. However, the complexes from either plastid type are capable of transcribing DNA regions containing genes for both the plastid rRNAs and for plastid proteins. In vitro transcripts were found to hybridize not only to DNA regions for mature in vivo RNA but also to adjacent regions, indicating synthesis of precursor RNA sequences by the transcriptionally active chromosomes.
从芥菜（Sinapis alba L.）幼苗的叶绿体和黄化质体中分离出了能够在体外进行RNA合成的DNA-蛋白质复合物（转录活性染色体）。对这些复合物的多肽模式分析表明，它们包含质体蛋白的一个特定子集，与可溶性或膜结合质体蛋白的总体模式不同。来自两种质体类型的DNA-蛋白质复合物有共同的多肽。然而，至少有几种多肽在叶绿体或黄化质体DNA-蛋白质复合物中高度富集。与来自任一质体类型的复合物相关的DNA的EcoRI限制性内切酶片段是相同的。它们与从高度纯化的叶绿体DNA获得的片段相同。叶绿体复合物的转录活性比黄化质体复合物的活性高十多倍。然而，来自任一质体类型的复合物都能够转录包含质体rRNA和质体蛋白基因的DNA区域。发现体外转录本不仅能与体内成熟RNA的DNA区域杂交，还能与相邻区域杂交，表明转录活性染色体合成了前体RNA序列。
