Lizama L, Holuigue L, Jordana X
Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, P. Universidad Católica de Chile, Santiago.
FEBS Lett. 1994 Aug 1;349(2):243-8. doi: 10.1016/0014-5793(94)00677-6.
The potato mitochondrial atp9 gene has a simple expression pattern. To determine where transcription initiates, primary mitochondrial RNAs were labeled by in vitro capping and hybridized to the 5' flanking sequences of the atp9 gene. A single transcription initiation region was identified. Primer extension and nuclease S1 protection analyses were used to precisely map the transcript 5' termini in this region. These results indicate that transcription initiates at 121-128 bp upstream of the atp9 open reading frame, in a sequence which does not present any homology with proposed consensus sequences for plant mitochondrial promoters. Nuclease S1 protection were also used to map 3' termini 67-71 nucleotides downstream of a putative single-stem loop structure.
马铃薯线粒体atp9基因具有简单的表达模式。为了确定转录起始位置，通过体外加帽对初级线粒体RNA进行标记，并与atp9基因的5'侧翼序列杂交。确定了一个单一的转录起始区域。使用引物延伸和核酸酶S1保护分析来精确绘制该区域转录本的5'末端图谱。这些结果表明，转录起始于atp9开放阅读框上游121 - 128 bp处，该序列与植物线粒体启动子的推测共有序列没有任何同源性。核酸酶S1保护分析还用于绘制推定的单茎环结构下游67 - 71个核苷酸处的3'末端图谱。
