Institute of Biology, Humboldt University,10115 Berlin, Germany.
Proc Natl Acad Sci U S A. 2010 Feb 16;107(7):3245-50. doi: 10.1073/pnas.0909400107. Epub 2010 Jan 28.
Bacterial group II introns encode maturase proteins required for splicing. In organelles of photosynthetic land plants, most of the group II introns have lost the reading frames for maturases. Here, we show that the plastidial maturase MatK not only interacts with its encoding intron within trnK-UUU, but also with six additional group II introns, all belonging to intron subclass IIA. Mapping analyses of RNA binding sites revealed MatK to recognize multiple regions within the trnK intron. Organellar group II introns are considered to be the ancestors of nuclear spliceosomal introns. That MatK associates with multiple intron ligands makes it an attractive model for an early trans-acting nuclear splicing activity.
细菌的第二类内含子编码剪接所需的成熟酶蛋白。在光合陆地植物的细胞器中，大多数第二类内含子失去了成熟酶的阅读框。在这里，我们表明质体成熟酶 MatK 不仅与 trnK-UUU 内的编码内含子相互作用，而且还与另外六个属于内含子类 IIA 的第二类内含子相互作用。对 RNA 结合位点的作图分析表明 MatK 可以识别 trnK 内含子内的多个区域。细胞器的第二类内含子被认为是核剪接内含子的祖先。MatK 与多个内含子配体结合，使其成为早期反式核剪接活性的有吸引力的模型。
