De Greve H, Dhaese P, Seurinck J, Lemmers M, Van Montagu M, Schell J
J Mol Appl Genet. 1982;1(6):499-511.
We have determined the complete nucleotide sequence of the gene for the crown gall enzyme, octopine synthase. The sequence was derived from cloned fragments of the Agrobacterium tumefaciens Ti plasmid Ach5. It displayed a continuous open reading frame encoding a polypeptide chain of 358 amino acids. The nucleotide positions corresponding to the 5' end and poly(A) addition site of the mature octopine synthase mRNA from a tobacco tumor cell line were determined by S1 nuclease mapping. Two sequences closely resembling transcriptional control regions found in eukaryotic genes transcribed by RNA polymerase II were identified in the flanking genomic DNA: a sequence 5'-TATTTAAA-3' was located 32 base pairs upstream from the initiation site of transcription, and a hexanucleotide 5'-AATAAT-3' occurred 17 base pairs in front of the poly(A) addition site. No Shine-Dalgarno sequence was present in the untranslated 5' leader sequence. The observations indicate that this DNA sequence, although naturally carried by a bacterial plasmid, is programmed as a functional plant gene.
我们已经确定了冠瘿酶章鱼碱合酶基因的完整核苷酸序列。该序列来自根癌土壤杆菌Ti质粒Ach5的克隆片段。它显示出一个连续的开放阅读框，编码一条由358个氨基酸组成的多肽链。通过S1核酸酶图谱分析确定了来自烟草肿瘤细胞系的成熟章鱼碱合酶mRNA的5'末端和多聚腺苷酸添加位点对应的核苷酸位置。在侧翼基因组DNA中鉴定出两个与RNA聚合酶II转录的真核基因中发现的转录控制区非常相似的序列：一个5'-TATTTAAA-3'序列位于转录起始位点上游32个碱基对处，一个六核苷酸5'-AATAAT-3'出现在多聚腺苷酸添加位点前17个碱基对处。在未翻译的5'前导序列中没有发现Shine-Dalgarno序列。这些观察结果表明，这个DNA序列虽然天然存在于细菌质粒中，但被编程为一个功能性的植物基因。
