Atypical DNA replication in the absence of origins in archaeon Haloferax volcanii

DNA复制被广泛接受为在基因组内的特定区域开始，称为“复制起点”。虽然起源以前被认为是生存所必需的，但在古菌Haloferax volcano ii中删除所有染色体复制起点没有不良影响，无起源细胞比野生型菌株生长快7.5%（Hawkins et al. 2013，Nature，doi：10.1038/nature12650）。复制的起始通常被很好地理解：起点识别蛋白将起点处的DNA重塑为更开放的结构，允许加载复制组件，这将形成将复制DNA的功能性“复制体”。关于DNA在没有起源的情况下是如何复制的知之甚少;起源和起源识别蛋白在H. volcanii，因此复制起始的替代模式必须发生。该项目旨在评估在缺乏复制起点的细胞中，复制的分子机制是如何改变的。将分析复制所需的组成部分，并评估依赖源的复制和不依赖源的复制之间的差异。

DNA replication is widely accepted to initiate at specific areas within the genome, known as 'origins of replication'. Whilst origins were previously thought to be essential for survival, deletion of all chromosomal origins of replication in archaeon Haloferax volcanii has no ill effect, with originless cells growing 7.5% faster than the wild type strain (Hawkins et al., 2013, Nature, doi:10.1038/nature12650). Initiation of replication is generally well understood: origin recognition proteins remodel DNA at the origin to a more open structure, allowing loading of replication components, which will form a functional 'replisome' that will replicate the DNA. Little is known about how DNA is replicated without origins; origins and origin recognition proteins are non-essential in H. volcanii, and thus an alternate mode of replication initiation must be occurring. This project aims to assess how the molecular mechanisms of replication are altered in cells lacking origins of replication. The components required for replication will be analysed and differences between origin-dependent and origin-independent replication will be assessed.