Duggin Iain G, Wake R Gerry, Bell Stephen D, Hill Thomas M
Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK.
Mol Microbiol. 2008 Dec;70(6):1323-33. doi: 10.1111/j.1365-2958.2008.06500.x. Epub 2008 Oct 17.
Bacteria that have a circular chromosome with a bidirectional DNA replication origin are thought to utilize a 'replication fork trap' to control termination of replication. The fork trap is an arrangement of replication pause sites that ensures that the two replication forks fuse within the terminus region of the chromosome, approximately opposite the origin on the circular map. However, the biological significance of the replication fork trap has been mysterious, as its inactivation has no obvious consequence. Here we review the research that led to the replication fork trap theory, and we aim to integrate several recent findings that contribute towards an understanding of the physiological roles of the replication fork trap. Likely roles include the prevention of over-replication, and the optimization of post-replicative mechanisms of chromosome segregation, such as that involving FtsK in Escherichia coli.
具有双向DNA复制起点的环状染色体细菌被认为利用“复制叉陷阱”来控制复制的终止。复制叉陷阱是一种复制暂停位点的排列方式，可确保两个复制叉在染色体的末端区域融合，该区域在环状图谱上大致与起点相对。然而，复制叉陷阱的生物学意义一直很神秘，因为其失活并没有明显的后果。在这里，我们回顾了导致复制叉陷阱理论的研究，并旨在整合一些近期的发现，这些发现有助于理解复制叉陷阱的生理作用。可能的作用包括防止过度复制，以及优化复制后染色体分离机制，例如大肠杆菌中涉及FtsK的机制。
