A mutant that affects the function of autonomously replicating sequences in yeast.
A mutant that affects the function of autonomously replicating sequences in yeast.
复制标题
影响酵母自主复制序列功能的突变体。
DOI：
10.1016/0022-2836(86)90030-6
复制
发表时间：
1986
影响因子：
5.6
通讯作者：
Tye,BK
中科院分区：
文献类型：
--
作者：
Sinha,P;Chang,V;Tye,BK
我们以前曾报道过一系列在酵母微染色体维持方面存在缺陷的mcmm突变体的分离。这些微小染色体是环状质粒，每个都含有一个自主复制序列(ARS)和一个着丝粒。其中一个突变体MCM2具有如下表型：在室温下，它只影响一些微染色体的稳定性，这取决于ARS的存在；而在高温下，它影响所有被测试的微染色体，而不考虑ARS的存在。在这里，我们证明了ARS的CMM缺陷及其依赖于温度的特异性可以用不含着丝粒序列的环状和线形质粒来证明。含有多个ARS的较大染色体在该突变体中也是不稳定的。进一步的分析表明，cm2突变导致的是环状微染色体的丢失，而不是异常分离。此外，这种突变似乎能刺激有丝分裂重组频率。Cm2突变体的这些特性与cm2突变导致ARSS的DNA复制启动缺陷的想法一致，ARSS是假定的染色体复制起源于酵母。
We previously reported the isolation of a series ofmcmmutants that are defective in the maintenance of minichromosomes in yeast. These minichromosomes are circular plasmids, each containing an autonomously replicating sequence (ARS) and a centromere. One of themcmmutants,mcm2, has the following phenotype: at room temperature it affects the stability of only some minichromosomes depending on theARSpresent, while at high temperature it affects all minichromosomes tested irrespective of theARSpresent. Here we show that themcmdefect as well as its temperature-dependent specificity forARSs can be demonstrated with circular as well as linear plasmids that do not contain centromeric sequences. Larger chromosomes containing multipleARSs are also unstable in this mutant. Further analyses indicate that themcm2mutation causes the loss, rather than the aberrant segregation, of the circular minichromosomes. In addition, this mutation appears to stimulate mitotic recombination frequencies. These properties of themcm2mutant are consistent with the idea that themcm2mutation results in a defect in the initiation of DNA replication atARSs, the putative chromosomal replication origins in yeast.