Norris V, Fralick J, Danchin A
Laboratoire des Processus Intégratifs Cellulaires, UPRES A CNRS 6037, IFR 'Systèmes Intégrés', Faculté des Sciences et Techniques, Université de Rouen, F76821 Mont Saint Aignan Cedex, France.
Mol Microbiol. 2000 Aug;37(4):696-702. doi: 10.1046/j.1365-2958.2000.02019.x.
A level of explanation in biology intermediate between macromolecules and cells has recently been proposed. This level is that of hyperstructures. One class of hyperstructures comprises the genes, mRNA, proteins and lipids that assemble to fulfil a particular function and disassemble when no longer required. To reason in terms of hyperstructures, it is essential to understand the factors responsible for their formation. These include the local concentration of sites on DNA and their cognate DNA-binding proteins. In Escherichia coli, the formation of a SeqA hyperstructure via the phenomenon of local concentration may explain how the binding of SeqA to hemimethylated GATC sequences leads to the sequestration of newly replicated origins of replication.
最近有人提出了生物学中一个介于大分子和细胞之间的解释层次。这个层次就是超结构层次。一类超结构由基因、信使核糖核酸、蛋白质和脂质组成,它们组装起来以实现特定功能,并在不再需要时解体。要从超结构的角度进行推理,必须了解负责其形成的因素。这些因素包括DNA上位点及其同源DNA结合蛋白的局部浓度。在大肠杆菌中,通过局部浓度现象形成的SeqA超结构或许可以解释SeqA与半甲基化GATC序列的结合是如何导致新复制的复制起点被隔离的。