Скачать или смотреть Eukaryotic DNA replication Initiation (CSIR NET)

Replication starts at multiple sites called origins of replication or replicator or autonomously replicating sequences (ARS). Multiple replicative proteins assemble on these sites to form pre initiation complex (pre-RC), ORC protein recognises and first binds with a replication origin recruits Cdc6 to form a platform for the loading of the Mcm2-7 helicase proteins, facilitated by the Cdt1. The ORC, Cdc6, and Cdt1 together are required for the stable association of the Mcm2-7 complex with replicative origins during the G1 phase of the cell cycle.
Once the pre-RC is formed, activation of the complex is triggered by two kinases CDK and DDK that help transition the pre-RC to the initiation complex before the initiation of DNA replication.
Cdc45 protein is a critical component for the conversion of the pre-replicative complex to the initiation complex. Cdc45 associates with chromatin after the beginning of initiation in late G1 stage and during the S phase of the cell cycle. The loading of Cdc45 onto chromatin is critical for loading other various replication proteins, including DNA pol alpha, DNA pol ε, RPA) and PCNA onto chromatin. GINS are essential for the interaction of Mcm and Cdc45 at the origins of replication during initiation and then at DNA replication forks as the replisome progresses. Cdc45, Mcm2-7 and GINS together form the CMG helicase, the replicative helicase of the replisome. Although the Mcm2-7 complex alone has weak helicase activity Cdc45 and GINS are required for robust helicase activity

   • Replication of DNA in Prokaryote (Initiati...