Daghfous D, Chatti A, Hammami R, Landoulsi A
Laboratoire de biochimie et de biologie moléculaire, faculté des sciences de Bizerte, 7021 Zarzouna, Tunisia.
Pathol Biol (Paris). 2009 May;57(3):e61-6. doi: 10.1016/j.patbio.2008.03.013. Epub 2008 Oct 11.
The Escherichia coli SeqA protein, a negative regulator of chromosome DNA replication, prevents the overinitiation of replication within one cell cycle by binding to hemimethylated GATC sequences in the replication origin, oriC. In addition to the hemimethylated DNA-binding activity, the SeqA protein has a self-association activity, which is also considered to be essential for its regulatory function in replication initiation. To study the SeqA protein biological activity, we performed a SeqA protein model to examine its architecture. SeqA has a bipartite structure composed of a large and small lobe. The SeqA spatial conformation contributes to its ability to bind to a pair of hemimethylated GATC sequences and to its cooperative behavior.
大肠杆菌SeqA蛋白是染色体DNA复制的负调控因子，它通过与复制起点oriC中的半甲基化GATC序列结合，防止在一个细胞周期内复制的过度起始。除了半甲基化DNA结合活性外，SeqA蛋白还具有自我缔合活性，这也被认为对其在复制起始中的调控功能至关重要。为了研究SeqA蛋白的生物学活性，我们构建了SeqA蛋白模型以研究其结构。SeqA具有由一个大的叶和一个小的叶组成的二分结构。SeqA的空间构象有助于其与一对半甲基化GATC序列结合的能力及其协同行为。
