The regular mechanism ofeukaryoticDNAreplicationAbstract:1、conserved initiator,divergent replicator2、 the origin recognition system3、replication licensing system4、SPF罗通郭鹏杨孔3thgroup:
The regular mechanism of eukaryotic DNA replication ⚫ Abstract： 1、conserved initiator,divergent replicator 2、the origin recognition system 3、replication licensing system 4、SPF 3th group：罗通 郭鹏 杨孔
Conservedintiator,divergentreplicatorORC82S.cerevksiaeARS1(125bp)83(ATITTTATA/G)TTTAT)≥2 ORCbinding sites11bpconsensusinallorisS.pombeARS2004;-750bp4ORC bindingsltesDrosophilsACEs18goneChorion Amplihication Origin1.5kb440bp-HumanB-globin LocusLCRGYIAY(LocallzedOrigin)75kbCHO DHFRLOCUSDHFR2BE2121(initistionZone)kb:022Fig1.Structureofgeneticallydissectedreplicationoriginsineukaryotes.ConsensusORCbindingsites areindicated inred.Additional sequences importantfar originactivity are shcwnin brown.Transcription units and regulatarysequencesare shown in green.Sites ofORC binding,whereknown,are indicated. Sites of initiation of replication are indicatedwith abidirectional arrowthroughabubbleassin
Conserved intiator,divergent replicator
Xenopus eggs and egg extractsXenopus eggs and egg extractsThree distinct system(ORC)the origin recognition systemthe replication licensing systemS phase-promoting factor ,SPF(Cdc7,CDKs)
Xenopus eggs and egg extracts ⚫ Xenopus eggs and egg extracts ⚫ Three distinct system: the origin recognition system（ORC） the replication licensing system S phase-promoting factor ,SPF （Cdc7,CDKs) ⚫ ⚫
the origin recognition system(ORC)In the early Xenopus embryo, replication originsare positioned randomly with respect to DNAsequencethen,origins become restricted to specific DNAseqences.It seem likely that The periodic spacing ofreplication origins is mediated by periodic bindingof ORC along the chromosomal DNATwo different model of periodic spacing of ORC
the origin recognition system （ORC） ⚫ In the early Xenopus embryo, replication origins are positioned randomly with respect to DNA sequence ⚫ then,origins become restricted to specific DNA seqences. ⚫ It seem likely that The periodic spacing of replication origins is mediated by periodic binding of ORC along the chromosomal DNA. ⚫ Two different model of periodic spacing of ORC
replication licensing system复制认证系统的组成：Fig.4认证模式的必需组件。起点的认证通过起点结合Mcm(2-7)蛋白实现的。Mcm(2-7)是必须的，但其功能不清楚可能是起解旋酶的作用认证系统的启动时间和抑制时间：Cdtl、Cdc6结合到起点认证开始，S期开始前受到抑制认证系统的调控和作用。Fig-5。认证系统的沉默受到多重调节（1、2、3、RLF-B/Cdt1抑制子，S、G2期积累，中后期转换时突然降解，此时认证系统被启动）
replication licensing system ⚫ 复制认证系统的组成： Fig.4认证模式的必需组 件。起点的认证通过 起点结合Mcm(2-7)蛋白实 现的。Mcm(2-7)是必须的，但其功能不清楚。 可能是起解旋酶的作用。 ⚫ 认证系统的启动时间和抑制时间：Cdt1、Cdc6 结合到起点认证开始，S期开始前受到抑制。 ⚫ 认证系统的调控和作用。Fig-5。 认证系统的沉默受到多重调节（1、2、3、 RLF-B/Cdt1抑制子，S、G2期积累，中后期转 换时突然降解，此时认证系统被启动）