Stahl D J, Rodermel S R, Bogorad L, Subramanian A R
Max Planck Institute for Molecular Genetics, Berlin, FRG.
Plant Mol Biol. 1993 Mar;21(6):1069-76. doi: 10.1007/BF00023603.
Several examples of the introduction of a gene from one gene complex into another (introgression) are found when chloroplast RP gene clusters are compared to those in Escherichia coli or cyanobacteria. Here we describe the transcript pattern of one such cluster from maize (Zea mays) that includes the genes for 4 subunits of the thylakoid ATP synthase (atpI, H, F, A) and the rps2 gene. Twelve transcript species covering the size range from 7,000 to 800 nt were identified in RNA isolated from dark-grown and greening maize seedlings, and several of them were characterized by reverse transcription analysis. A major species of 6,200 nt, with its 5' end at 181 nt upstream of the initiating ATG of rps2, contained the transcripts of all the 5 genes. Two further sets of transcripts having their 5' ends ca. 120 and 50 nt upstream of the initiation codons of the atpI and atpH genes were also identified. Thus, this plastid gene cluster in maize is functionally organized as an operon with additional regulatory features to allow for increased accumulation of mRNAs for the thylakoid components.
当将叶绿体RP基因簇与大肠杆菌或蓝细菌中的基因簇进行比较时，会发现几个将一个基因复合体中的基因导入另一个基因复合体（基因渐渗）的例子。在这里，我们描述了来自玉米（Zea mays）的一个这样的基因簇的转录模式，该基因簇包括类囊体ATP合酶4个亚基（atpI、H、F、A）的基因以及rps2基因。在从黑暗生长和正在变绿的玉米幼苗中分离的RNA中鉴定出了12种转录本，其大小范围从7000到800 nt，其中几种通过逆转录分析进行了表征。一种主要的6200 nt转录本，其5'端位于rps2起始ATG上游181 nt处，包含了所有5个基因的转录本。还鉴定出另外两组转录本，其5'端分别位于atpI和atpH基因起始密码子上游约120和50 nt处。因此，玉米中的这个质体基因簇在功能上被组织成一个操纵子，具有额外的调控特征，以允许增加类囊体成分mRNA的积累。
