Purton S, Gray J C
Botany School, University of Cambridge, UK.
Mol Gen Genet. 1989 May;217(1):77-84. doi: 10.1007/BF00330945.
The gene rpoA, encoding a protein homologous to the alpha subunit of RNA polymerase from Escherichia coli has been located in pea chloroplast DNA downstream of the petD gene for subunit IV of the cytochrome b-f complex. Nucleotide sequence analysis has revealed that rpoA encodes a polypeptide of 334 amino acid residues with a molecular weight of 38916. Northern blot analysis has shown that rpoA is co-transcribed with the gene for ribosomal protein S11. A lacZ-rpoA gene-fusion has been constructed and expressed in E. coli. Antibodies raised against the fusion protein have been employed to demonstrate the synthesis of the rpoA gene product in isolated pea chloroplasts. Western blot analysis using these antibodies and antibodies against the RNA polymerase core enzyme from the cyanobacterium, Anabaena 7120, has revealed the presence of the gene product in a crude RNA polymerase preparation from pea chloroplasts.
编码与大肠杆菌RNA聚合酶α亚基同源蛋白的rpoA基因，位于豌豆叶绿体DNA中细胞色素b-f复合体IV亚基的petD基因下游。核苷酸序列分析表明，rpoA编码一个由334个氨基酸残基组成、分子量为38916的多肽。Northern印迹分析表明，rpoA与核糖体蛋白S11的基因共同转录。构建了lacZ-rpoA基因融合体并在大肠杆菌中表达。用针对融合蛋白产生的抗体来证明在分离的豌豆叶绿体中rpoA基因产物的合成。使用这些抗体以及针对蓝细菌鱼腥藻7120的RNA聚合酶核心酶的抗体进行的Western印迹分析，揭示了在豌豆叶绿体的粗RNA聚合酶制剂中存在该基因产物。
