EASE OF DNA UNWINDING IS A CONSERVED PROPERTY OF YEAST REPLICATION ORIGINS
EASE OF DNA UNWINDING IS A CONSERVED PROPERTY OF YEAST REPLICATION ORIGINS
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DOI：
10.1093/nar/21.3.555
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发表时间：
1993-02-11
影响因子：
14.9
通讯作者：
KOWALSKI, D
中科院分区：
文献类型：
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作者：
NATALE, DA;UMEK, RM;KOWALSKI, D
自主复制序列（ARS）元件作为质粒复制起点。我们对H4 ARS和ARS 307的研究已经确定了对DNA解旋元件（DUE）的需求，这是一种广泛的、易于解旋的序列，位于基本共识的3'端，可能有助于起点的打开。在这份报告中，我们研究了内在的容易解开各种ARS元素使用（1）单链特异性核酸酶探测DNA解旋在负超螺旋质粒，（2）计算机程序，计算DNA螺旋稳定性的核苷酸序列。与染色体III上的复制起点相关的ARS元件是核酸酶超敏感的，并且螺旋稳定性最小值正确地预测了超敏感位点的位置和层次。所有研究充分的ARS元件（其中基本共有序列已经通过突变分析鉴定）都含有紧邻共有序列3'的100-bp低螺旋稳定性区域，正如在原核M13载体内通过突变产生的ARS元件一样。在所有情况下，螺旋稳定性水平均低于因DUE突变而失活的ARS 307衍生物。我们的研究结果表明，直接在ARS共有序列3'端的宽区域的DNA解旋的容易性是酵母复制起点的保守性质。
Autonomously replicating sequence (ARS) elements function as plasmid replication origins. Our studies of the H4 ARS and ARS307 have established the requirement for a DNA unwinding element (DUE), a broad easily-unwound sequence 3' to the essential consensus that likely facilitates opening of the origin. In this report, we examine the intrinsic ease of unwinding a variety of ARS elements using (1) a single-strand-specific nuclease to probe for DNA unwinding in a negatively-supercoiled plasmid, and (2) a computer program that calculates DNA helical stability from the nucleotide sequence. ARS elements that are associated with replication origins on chromosome III are nuclease hypersensitive, and the helical stability minima correctly predict the location and hierarchy of the hypersensitive sites. All well-studied ARS elements in which the essential consensus sequence has been identified by mutational analysis contain a 100-bp region of low helical stability immediately 3' to the consensus, as do ARS elements created by mutation within the prokaryotic M 1 3 vector. The level of helical stability is, in all cases, below that of ARS307 derivatives inactivated by mutations in the DUE. Our findings indicate that the ease of DNA unwinding at the broad region directly 3' to the ARS consensus is a conserved property of yeast replication origins.