Li Y Q, Ye L Z, Sugita M, Sugiura M
Center for Gene Research, Nagoya University, Japan.
Nucleic Acids Res. 1991 Jun 11;19(11):2987-91. doi: 10.1093/nar/19.11.2987.
We have previously identified three chloroplast ribonucleoproteins and characterized their cDNAs. Here we present the genomic organization, sequence and expression of one of their genes. The 31 kd ribonucleoprotein (cp31) from tobacco (Nicotiana sylvestris) chloroplasts is coded for by a single-copy nuclear gene. This gene was isolated and its sequence was determined. The gene contains four exons and three introns. The position of its first intron is conserved among the genes for the maize abscisic acid-induced glycine-rich protein, the human hnRNP A1 protein and cp31. The transcription start site was determined to be 168 bp upstream from the translational initiation codon in both leaf and root tissues. No alternatively spliced transcripts was detected, suggesting that a diversity of chloroplast ribonucleoproteins is generated probably by gene amplification rather than alternative splicing.
我们之前已鉴定出三种叶绿体核糖核蛋白并对其cDNA进行了表征。在此，我们展示了其中一个基因的基因组结构、序列及表达情况。烟草（林烟草）叶绿体中的31 kd核糖核蛋白（cp31）由单拷贝核基因编码。该基因被分离并测定了序列。此基因包含四个外显子和三个内含子。其第一个内含子的位置在玉米脱落酸诱导的富含甘氨酸蛋白、人类hnRNP A1蛋白及cp31的基因中是保守的。在叶片和根组织中，转录起始位点被确定为翻译起始密码子上游168 bp处。未检测到可变剪接转录本，这表明叶绿体核糖核蛋白的多样性可能是通过基因扩增而非可变剪接产生的。
