Morikami A, Nakamura K
Laboratory of Biochemistry, School of Agriculture, Nagoya University, Japan.
Biosci Biotechnol Biochem. 1993 Sep;57(9):1530-5. doi: 10.1271/bbb.57.1530.
The atpA gene of pea mitochondria coding for the alpha-subunit of F1F0-ATPase (ATP synthase) is carried on four types of genomic segments generated by recombination, and two of these segments contain the atp9 gene coding for the subunit 9 of F1F0ATPase in the 5'-upstream region of atpA in an opposite orientation. The atpA and atp9 genes were separated by a spacer of 2112 bp, which does not contain any open reading frame. Pea mitochondria contained at least four atpA transcripts of 4.5, 2.7, 2.3, and 1.8 kb and at least three atp9 transcripts of 1.35, 0.6, and 0.4 kb. Mapping of these transcripts by northern blot hybridization, primer extension, and S1-nuclease mapping indicated that multiple transcripts of atpA differ in their length both at their 5'- and 3'-termini. On the other hand, three transcripts of atp9 differed in their length only at their 5'-termini. It was found that the 5'-terminal sequence of the 4.5-kb transcript of atpA is complementary to the 5'-terminal part of the 1.35- and 0.6-kb transcripts of atp9 for 705 and 4 nucleotides, respectively.
豌豆线粒体中编码F1F0 - ATP酶（ATP合酶）α亚基的atpA基因由重组产生的四种基因组片段携带，其中两个片段在atpA基因5'上游区域以相反方向包含编码F1F0ATP酶亚基9的atp9基因。atpA基因和atp9基因被一个2112 bp的间隔区隔开，该间隔区不包含任何开放阅读框。豌豆线粒体含有至少四种长度分别为4.5、2.7、2.3和1.8 kb的atpA转录本以及至少三种长度分别为1.35、0.6和0.4 kb的atp9转录本。通过Northern印迹杂交、引物延伸和S1核酸酶图谱分析对这些转录本进行定位，结果表明atpA的多个转录本在其5'和3'末端的长度均不同。另一方面，atp9的三种转录本仅在其5'末端长度不同。研究发现，atpA基因4.5 kb转录本的5'末端序列分别与atp9基因1.35 kb和0.6 kb转录本的5'末端部分有705个和4个核苷酸的互补。
