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

DNA复制被广泛接受，在基因组中的特定区域开始，被称为复制的起源。虽然起源以前被认为是生存所必需的，但删除考古盐藻火山中所有复制的染色体起源没有不良影响，没有起源的细胞生长速度比野生型菌株快7.5%(Hawkins等，2013年，《自然》，DOI：10.1038/Nature12650)。复制的启动通常是很好的理解：起源识别蛋白将起始处的DNA重塑为更开放的结构，允许加载复制组件，这将形成一个复制DNA的功能性“复制体”。人们对DNA如何在没有起始点的情况下复制知之甚少；起始点和起始点识别蛋白在火山杆菌中不是必需的，因此必须发生另一种复制起始模式。这个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，并评估依赖原产地的复制和独立于原产地的复制之间的差异。

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.