Evolution of homing endonuclease structure and function

所有生物体的基因组都含有数量不等的“垃圾DNA”，即不编码功能蛋白质或RNA分子的DNA，也没有任何明显的功能。其中一些垃圾DNA是由小的遗传元件组成的，这些遗传元件的功能是促进它们在基因组内和基因组之间的传播。在这样做的过程中，这种所谓的自私DNA可以通过干扰基本基因、扰乱基因表达模式和促进染色体重排来深刻影响基因组结构和功能。我的研究项目通过检查这种元素用来促进其流动性的蛋白质的功能需求，来检查一种自私DNA促进其在基因组之间传播的分子机制。这种蛋白质被称为归巢内切酶，以位点特异性和序列耐受的方式与DNA结合，并在其目标位点引入双链断裂，从而促进元件的流动性。我们对归巢内切酶识别和切割特定DNA序列的机制感兴趣。这项研究是普遍感兴趣的，因为它解决了蛋白质如何在整个基因组的背景下识别非常小的DNA序列的问题。此外，这些研究有可能导致DNA内切酶的工程，使其在基因组中所需的位置切割，并应用于基因靶向。

The genomes of all organisms contain a variable amount of "junk DNA", DNA that does not code for functional proteins or RNA molecules, and does not have any apparent function. Some of this junk DNA is composed of small genetic elements that function to promote their own spread within and between genomes. In doing so, this so-called selfish DNA can profoundly influence genome structure and function by interrupting essential genes, by perturbing gene expression patterns, and by promoting chromosomal re-arrangements. My research program examines the molecular mechanisms by which one type of selfish DNA promotes its spread between genomes by examining the functional requirements of the protein used by the element to promote its mobility. This protein, called a homing endonuclease, binds DNA in a site-specific and sequence tolerant fashion, and introduces a double-strand break at its target site, which promotes mobility of the element. We are interested in the mechanisms by which homing endonucleases recognize and cleave specific DNA sequences. This research is of general interest as it addresses the problem of how proteins recognize a very small stretch of DNA sequence in the context of the entire genome. In addition, there is the potential that these studies will lead to engineering of DNA endonucleases to cleave at desired locations within genomes, with applications in gene targeting.