The Saccharomyces cerevisiae helicase Rrm3p facilitates replication past nonhistone protein-DNA complexes
The Saccharomyces cerevisiae helicase Rrm3p facilitates replication past nonhistone protein-DNA complexes
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DOI：
10.1016/s1097-2765(03)00456-8
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发表时间：
2003-12-01
期刊：
影响因子：
16
通讯作者：
Zakian, VA
中科院分区：
文献类型：
--
作者：
Ivessa, AS;Lenzmeier, BA;Zakian, VA
酿酒酵母RRM3基因编码一个5‘到3’的DNA解旋酶。虽然大多数酵母基因组的复制不依赖于Rrm3p，但在Rrm3p缺失的情况下，复制叉会在估计的1400个离散位点暂停并经常断裂，包括tRNA基因、着丝粒、非活性复制起点和转录沉默子。这些复制缺陷与s期内检查点的激活有关。检查点的激活对rrm3Delta细胞的生存至关重要，特别是在低温下。每个复制受到Rrm3p影响的位点被组装成一个非核体蛋白- dna复合体。在tRNA基因和沉默交配型位点上，这些复合物的破坏消除了对Rrm3p的依赖。这些数据表明，Rrm3p DNA解旋酶帮助复制叉穿过蛋白质-DNA复合物，这是在每个S期遇到的自然发生的障碍。
The Saccharomyces cerevisiae RRM3 gene encodes a 5' to 3' DNA helicase. While replication of most of the yeast genome was not dependent upon Rrm3p, in its absence, replication forks paused and often broke at an estimated 1400 discrete sites, including tRNA genes, centromeres, inactive replication origins, and transcriptional silencers. These replication defects were associated with activation of the intra-S phase checkpoint. Activation of the checkpoint was critical for viability of rrm3Delta cells, especially at low temperatures. Each site whose replication was affected by Rrm3p is assembled into a nonnucleosomal protein-DNA complex. At tRNA genes and the silent mating type loci, disruption of these complexes eliminated dependence upon Rrm3p. These data indicate that the Rrm3p DNA helicase helps replication forks traverse protein-DNA complexes, naturally occurring impediments that are encountered in each S phase.