Cvetic Christin, Walter Johannes C
Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, 240 Longwood Avenue, Boston, MA 02115, USA.
Semin Cell Dev Biol. 2005 Jun;16(3):343-53. doi: 10.1016/j.semcdb.2005.02.009.
Initiation of eukaryotic DNA replication commences when the origin recognition complex (ORC) binds to DNA, recruiting helicases, polymerases, and necessary cofactors. While the biochemical mechanism and factors involved in replication initiation appear to be highly conserved, the DNA sequences at which these events take place in different organisms are not. Thus, while ORC appears to bind to specific DNA sequences in budding yeast, there is increasing new evidence that metazoan ORC complexes do not rely on sequence to be directed to origins of replication. Here, we review examples of specific and non-specific initiation, and we consider what, if not DNA sequence, accounts for DNA binding of ORC to defined regions in eukaryotic genomes.
当真核生物的起始识别复合物（ORC）与DNA结合，招募解旋酶、聚合酶和必要的辅助因子时，真核生物DNA复制就开始了。虽然复制起始所涉及的生化机制和因子似乎高度保守，但这些事件在不同生物体中发生的DNA序列却并非如此。因此，虽然ORC似乎能与芽殖酵母中的特定DNA序列结合，但越来越多的新证据表明，后生动物的ORC复合物并不依赖序列来定位到复制起点。在这里，我们回顾了特异性和非特异性起始的例子，并思考了如果不是DNA序列，那么是什么因素导致ORC与真核生物基因组中的特定区域结合。
