Smooker P M, Schmidt J, Subramanian A R
Max-Planck-Institut für Molekuläre Genetik, Abteilung Wittmann, Berlin-Dahlem, Germany.
Biochimie. 1991 Jun;73(6):845-51. doi: 10.1016/0300-9084(91)90064-8.
The majority of chloroplast ribosomal proteins are encoded in the nuclear genome. In order to characterize these proteins through their mRNA, we have previously constructed a spinach cDNA expression library and raised antisera to several spinach chloroplast ribosomal proteins. Here we describe the immuno isolation of cDNA clones encoding protein L11 and its chloroplast-targeting presequence. The cytoplasmic precursor form of L11 is 224 amino acid residues long (Mr 23,662); the mature L11 and the transit sequence are predicted to be of approximately 159 and approximately 65 residues, respectively. The predicted chloroplast L11 is significantly longer than the E coli L11, but similar (in size) to archaebacterial and yeast cytoplasmic L11. In sequence it is closer to E coli L11 (54% identity) than to the archaebacterial (32%) or yeast (23%) proteins. These results and the conservation of the contexts of the 3 methyl modified residues found in E coli L11 are discussed in the light of the endosymbiont theory and nuclear relocation of the rp/KAJL gene cluster.
大多数叶绿体核糖体蛋白是由核基因组编码的。为了通过其mRNA来鉴定这些蛋白，我们之前构建了一个菠菜cDNA表达文库，并制备了针对几种菠菜叶绿体核糖体蛋白的抗血清。在此，我们描述了编码蛋白L11及其叶绿体靶向前序列的cDNA克隆的免疫分离。L11的细胞质前体形式长224个氨基酸残基（分子量23,662）；预测成熟的L11和转运序列分别约为159个和约65个残基。预测的叶绿体L11比大肠杆菌L11长得多，但（大小）与古细菌和酵母细胞质L11相似。在序列上，它与大肠杆菌L11（54%同一性）比与古细菌（32%）或酵母（23%）蛋白更接近。根据内共生理论和rp/KAJL基因簇的核定位，讨论了这些结果以及在大肠杆菌L11中发现的3个甲基修饰残基的上下文保守性。
