Kuroda Hiroshi, Suzuki Haruka, Kusumegi Takahiro, Hirose Tetsuro, Yukawa Yasushi, Sugiura Masahiro
Graduate School of Natural Sciences, Nagoya City University, Yamanohata, Mizuho, Nagoya, Japan.
Plant Cell Physiol. 2007 Sep;48(9):1374-8. doi: 10.1093/pcp/pcm097. Epub 2007 Jul 29.
The plastid gene psbC encodes the CP43 subunit of PSII. Most psbC mRNAs of many organisms possess two possible initiation codons, AUG and GUG, and their coding regions are generally annotated from the upstream AUG. Using a chloroplast in vitro translation system, we show here that translation of the tobacco plastid psbC mRNA initiates from the GUG. This mRNA possesses a long Shine-Dalgarno (SD)-like sequence, GAGGAGGU, nine nucleotides upstream of the GUG. Point mutations in this sequence abolished translation, suggesting that a strong interaction between this extended SD-like sequence and the 3' end of 16S rRNA facilitates translation initiation from the GUG.
质体基因psbC编码光系统II的CP43亚基。许多生物体的大多数psbC mRNA都有两个可能的起始密码子，即AUG和GUG，其编码区通常从上游的AUG开始注释。我们在此利用叶绿体体外翻译系统表明，烟草质体psbC mRNA的翻译起始于GUG。该mRNA在GUG上游九个核苷酸处有一个长的类似Shine-Dalgarno（SD）的序列，即GAGGAGGU。该序列中的点突变消除了翻译，这表明这个延伸的类似SD的序列与16S rRNA的3'末端之间的强相互作用促进了从GUG起始的翻译。
