Cotranscription of genes encoding the small and large subunits of ribulose-1,5-bisphosphate carboxylase in the cyanobacterium Anabaena 7120.
Cotranscription of genes encoding the small and large subunits of ribulose-1,5-bisphosphate carboxylase in the cyanobacterium Anabaena 7120.
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蓝藻鱼腥藻 7120 中编码核酮糖-1,5-二磷酸羧化酶小亚基和大亚基的基因的共转录。
DOI：
10.1073/pnas.81.19.5961
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发表时间：
1984
影响因子：
11.1
通讯作者：
Haselkorn,R
中科院分区：
文献类型：
--
作者：
Nierzwicki-Bauer,SA;Curtis,SE;Haselkorn,R
在丝状蓝细菌鱼腥藻中，核酮糖-1,5-二磷酸羧化酶小亚基（rbcS）的基因与编码同一酶的大亚基（rbcL）的基因连接并一起转录。这两个基因由 545 个碱基对 (bp) 的间隔区分开，该间隔区不包含开放阅读框。两个基因均与主要的 3.1 KB 转录物杂交，该转录物起始于 rbcL 编码区上游 414 bp。转录起始位点之前 14-8 bp 的核苷酸序列类似于良好的大肠杆菌启动子，但 -35 区域中的序列却不然。蓝藻小亚基基因氨基端侧翼的序列与真核小亚基基因的转运肽之间没有明显的关系。鱼腥藻 rbcS 基因在氨基酸水平上与来自单细胞蓝藻 Anacystis 的基因有 61% 同源性，与来自真核生物的相应核基因有 37-38% 同源性。相比之下，鱼腥藻 rbcL 基因在氨基酸水平上与来自植物叶绿体的 rbcL 基因大约等于 86% 同源性。共转录满足两个基因协调表达的要求之一，这两个基因的产物在成熟酶中需要等摩尔量。 rbcL-rbcS 转录本在光照条件下生长的满江红鱼腥藻和黑暗条件下以果糖为食的鱼腥藻中同样丰富。
In the filamentous cyanobacterium Anabaena, the gene for the small subunit (rbcS) of ribulose-1,5-bisphosphate carboxylase is linked to and transcribed together with the gene encoding the large subunit (rbcL) of the same enzyme. The two genes are separated by a spacer of 545 base pairs (bp) that does not contain an open reading frame. Both genes hybridize with a predominant 3.1-kilobase transcript that initiates 414 bp upstream from the rbcL coding region. The nucleotide sequence 14-8 bp preceding the transcription start site resembles a good Escherichia coli promoter, but the sequence in the -35 region does not. There is no obvious relationship between the sequence flanking the amino terminus of the cyanobacterial small subunit gene and the transit peptide of eukaryotic small subunit genes. The Anabaena rbcS gene is 61% homologous at the amino acid level with the gene from the unicellular cyanobacterium Anacystis and 37-38% homologous with the corresponding nuclear genes from eukaryotes. In contrast, the Anabaena rbcL gene is approximately equal to 86% homologous at the amino acid level with the rbcL genes from plant chloroplasts. Cotranscription satisfies one of the requirements for coordinate expression of the two genes whose products are needed in equimolar amounts in the mature enzyme. The rbcL-rbcS transcript is equally abundant in Anabaena azollae grown in the light or on fructose in the dark.