Bacterial group II introns: splicing, function and evolution

我们的研究目标是研究与细菌II族内含子相关的剪接、功能和进化问题。在第一个倡议，我们研究II组内含子的反式剪接，以解决II组内含子，核内含子和五个小rna之间的进化关系，它们是剪接机制的一部分，剪接体。其次，我们正在探索细菌细胞中II族内含子的各种剪接途径。最后，我们研究了这些可逆行元件在细菌物种之间的偶联和转导传播。我们的模型系统是l。乳球菌LtrB II组内含子。乳酸菌是一种重要的工业低G+C革兰氏阳性菌，主要用于乳制品行业生产奶酪和酸奶。会。LtrB与乳酸菌的pRS01和pAH90质粒以及染色体性别因子相关。因此，我们正在研究乳酸菌性因子在细菌细胞间的结合转移是否能支持乳酸菌的传播。它传递LtrB内含子。我们还研究了Ll。LtrB内含子可通过各种噬菌体（转导）在细菌界内播散。在乳酸菌中携带内含子的元素转移到不同的细菌种类后，我们将研究乳酸菌的再插入。LtrB在新细胞环境中的移动II族内含子。重新插入Ll。LtrB内含子进入同源和非同源位点的研究。我们也在研究细菌细胞中II族内含子的各种剪接途径及其在反式中断裂和剪接的能力。这将使我们能够解决核内含子的起源和它们的剪接机制。

The goal of our research program is to study splicing, function and evolutionary questions related to bacterial group II introns. In a first initiative we study trans-splicing of group II introns in order to address the evolutionary relationships between group II introns, nuclear introns and the five small RNAs that are part of the splicing machinery, the spliceosome. Secondly, we are exploring the various splicing pathways of group II introns in bacterial cells. Finally, we study the dissemination of these retromobile elements by conjugation and transduction between bacterial species. Our model system is the Ll.LtrB group II intron from Lactococcus lactis. L. lactis is an industrially important low G+C Gram-positive bacterium mainly used in the dairy industry for the production of cheese and yogurt. Ll.LtrB was found associated with different conjugative elements in L. lactis: the pRS01 and pAH90 plasmids and the chromosomal sex factor. We are thus studying if the transfer by conjugation of the L. lactis sex factor between bacterial cells can support the spread of the Ll.LtrB intron it conveys. We also study if the Ll.LtrB intron can be disseminated in the bacterial kingdom by various bacteriophages (transduction). After transfer of the intron-carrying elements from L. lactis to different bacterial species, we will study the reinsertion of the Ll.LtrB mobile group II intron in its new cell environment. Reinsertion of the Ll.LtrB intron into homologous and non-homologous sites will be studied. We are also studying the various splicing pathways of group II introns in bacterial cells and their capacity to be fragmented and still splice in trans. This will allow us to address the origin of nuclear introns and their splicing machinery.