Pancic P G, Strotmann H, Kowallik K V
Institut für Biochemie der Pflanzen, Heinrich-Heine-Universität Düsseldorf, Germany.
J Mol Biol. 1992 Mar 20;224(2):529-36. doi: 10.1016/0022-2836(92)91017-j.
We have cloned and sequenced a 5200 base restriction fragment and an overlapping 3100 base fragment of the large single copy region of the chloroplast genome of the diatom Odontella sinensis, which hybridized to several ATPase gene probes. These fragments contain six closely linked reading frames that were identified as atpI, atpH, atpG, atpF, atpD, and atpA, coding for subunits IV, III, II, I, delta, and alpha, respectively. Remarkably, the genes atpG and atpD, which are nucleus-encoded in chlorophyll a + b plants, are present in the Odontella chloroplast gene cluster. They map at the same positions as in cyanobacteria. The genes atpD and atpF overlap by four base-pairs as in certain photosynthetic and heterotrophic eubacteria. Upstream from the atpA gene cluster an open reading frame coding for 251 amino acid residues was found, which shows sequence similarity to ATP-binding subunits of periplasmic prokaryotic and eukaryotic transport systems. No similar reading frame is present in the land plant chloroplast genomes analysed so far. Sequences and arrangement of the genes are discussed with respect to the peculiar evolution of the chlorophyll a + c-containing chromophytic plastids.
我们克隆并测序了中华齿状藻叶绿体基因组大单拷贝区域的一个5200个碱基的限制性片段和一个重叠的3100个碱基的片段，这些片段与几个ATP酶基因探针杂交。这些片段包含六个紧密相连的阅读框，分别被鉴定为atpI、atpH、atpG、atpF、atpD和atpA，它们分别编码亚基IV、III、II、I、δ和α。值得注意的是，在叶绿素a + b植物中由细胞核编码的atpG和atpD基因存在于中华齿状藻叶绿体基因簇中。它们的定位与蓝细菌中的相同。atpD和atpF基因如在某些光合和异养真细菌中一样，重叠四个碱基对。在atpA基因簇上游发现了一个编码251个氨基酸残基的开放阅读框，它与周质原核和真核运输系统的ATP结合亚基具有序列相似性。在迄今为止分析的陆地植物叶绿体基因组中没有发现类似的阅读框。针对含叶绿素a + c的色素植物质体的特殊进化，讨论了这些基因的序列和排列。
