High-resolution analysis of four efficient yeast replication origins reveals new insights into the ORC and putative MCM binding elements.
High-resolution analysis of four efficient yeast replication origins reveals new insights into the ORC and putative MCM binding elements.
复制标题
DOI：
10.1093/nar/gkr301
复制
发表时间：
2011-08
影响因子：
14.9
通讯作者：
Weinreich M
中科院分区：
文献类型：
--
作者：
Chang F;May CD;Hoggard T;Miller J;Fox CA;Weinreich M
在芽殖酵母中，真核起始蛋白ORC（起源识别复合物）结合到由11 bp ACS元件和相邻B1元件组成的二分序列。然而，基因组包含更多的匹配到这个共识比实际结合ORC或功能作为体内的起源。虽然ORC依赖性加载的复制MCM解旋酶在起源增强了远端B2元素，鲜为人知的是这个元素。在这里，我们分析了四个高度活跃的起源（ARS 309，ARS 319，ARS 606和ARS 607）的连接子扫描诱变，发现邻近ACS的序列大大有助于起源活动和ORC结合。使用四个额外的B2元件的序列，我们产生了B2多序列比对，并确定了一个共享的，简并的8 bp序列，富集在228个已知的起源。此外，我们的高分辨率分析显示，并非所有的起源都存在于无核小体区域内：一类Sir2调节的起源具有稳定定位的核小体重叠或靠近B2。这项研究说明了酵母起源结构的保守性和灵活性，以促进ORC结合和起源活性，并有助于解释为什么与ORC结合位点的强匹配不足以识别基因组内的起源。
In budding yeast, the eukaryotic initiator protein ORC (origin recognition complex) binds to a bipartite sequence consisting of an 11 bp ACS element and an adjacent B1 element. However, the genome contains many more matches to this consensus than actually bind ORC or function as origins in vivo. Although ORC-dependent loading of the replicative MCM helicase at origins is enhanced by a distal B2 element, less is known about this element. Here, we analyzed four highly active origins (ARS309, ARS319, ARS606 and ARS607) by linker scanning mutagenesis and found that sequences adjacent to the ACS contributed substantially to origin activity and ORC binding. Using the sequences of four additional B2 elements we generated a B2 multiple sequence alignment and identified a shared, degenerate 8 bp sequence that was enriched within 228 known origins. In addition, our high-resolution analysis revealed that not all origins exist within nucleosome free regions: a class of Sir2-regulated origins has a stably positioned nucleosome overlapping or near B2. This study illustrates the conserved yet flexible nature of yeast origin architecture to promote ORC binding and origin activity, and helps explain why a strong match to the ORC binding site is insufficient to identify origins within the genome.
登录
查看更多内容
影响因子：
56.9
作者：
MARAHRENS, Y;STILLMAN, B
通讯作者：
STILLMAN, B
影响因子：
10.5
作者：
Eaton, Matthew L.;Galani, Kyriaki;MacAlpine, David M.
通讯作者：
MacAlpine, David M.
影响因子：
10.5
作者：
Nieduszynski, Conrad A.;Knox, Yvonne;Donaldson, Anne D.
通讯作者：
Donaldson, Anne D.
影响因子：
16
作者：
Crampton, Amber;Chang, FuJung;Weinreich, Michael
通讯作者：
Weinreich, Michael
影响因子：
5.8
作者：
Larkin, M. A.;Blackshields, G.;Higgins, D. G.
通讯作者：
Higgins, D. G.