Cotranscription, deduced primary structure, and expression of the chloroplast-encoded rbcL and rbcS genes of the marine diatom Cylindrotheca sp. strain N1.
Cotranscription, deduced primary structure, and expression of the chloroplast-encoded rbcL and rbcS genes of the marine diatom Cylindrotheca sp. strain N1.
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DOI：
10.1016/s0021-9258(18)38114-6
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发表时间：
1991-04
期刊：
影响因子：
--
通讯作者：
S. Hwang;F. Tabita
中科院分区：
文献类型：
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作者：
S. Hwang;F. Tabita
来自海洋硅藻 Cylindrotheca sp 的核酮糖-1,5-二磷酸羧化酶/加氧酶的一级结构。菌株N1已确定。与高等植物和绿藻不同，编码核酮糖-1,5-二磷酸羧化酶/加氧酶大亚基和小亚基的基因是叶绿体编码的并且密切相关（Hwang和Tabita，1989）。 N1 菌株中的 rbcL 和 rbcS 基因是共转录的，并被 46 个核苷酸碱基对的基因间区域分开。核糖体结合位点和潜在的启动子序列与先前确定的叶绿体序列高度同源。硅藻大亚基和小亚基推导的一级结构的比较表明与先前确定的细菌序列具有显着的同源性；与蓝藻、绿藻和高等植物的大小亚基的同源性要少得多。虽然高水平的重组硅藻大亚基可以在大肠杆菌中表达，但合成的蛋白质主要是不溶性的并且不能形成活性的十六聚体酶。 Edman降解研究表明，从菌株N1中分离出的大亚基的氨基末端被阻断，这表明负责加工和随后组装大亚基和小亚基的机制类似于其他真核核酮糖-1,5-二磷酸羧化酶/加氧酶蛋白的情况，尽管具有独特的原核基因排列和序列同源性。
The primary structure of ribulose-1,5-bisphosphate carboxylase/oxygenase from the marine diatom Cylindrotheca sp. strain N1 has been determined. Unlike higher plants and green algae, the genes encoding the large and the small subunits of ribulose-1,5-bisphosphate carboxylase/oxygenase are chloroplast-encoded and closely associated (Hwang and Tabita, 1989). The rbcL and rbcS genes in strain N1 are cotranscribed and are separated by an intergenic region of 46 nucleotide base pairs. Ribosome binding sites and a potential promoter sequence were highly homologous to previously determined chloroplast sequences. Comparison of the deduced primary structure of the diatom large and small subunits indicated significant homology to previously determined sequences from bacteria; there was much less homology to large and small subunits from cyanobacteria, green algae, and higher plants. Although high levels of recombinant diatom large subunits could be expressed in Escherichia coli, the protein synthesized was primarily insoluble and incapable of forming an active hexadecameric enzyme. Edman degradation studies indicated that the amino terminus of the large subunit isolated from strain N1 was blocked, suggesting that the mechanism responsible for processing and subsequent assembly of large and small subunits resembles the situation found with other eucaryotic ribulose-1,5-bisphosphate carboxylase/oxygenase proteins, despite the distinctive procaryotic gene arrangement and sequence homology.