ALTERATIONS IN THE ADENINE-PLUS-THYMINE-RICH REGION OF CEN3 AFFECT CENTROMERE FUNCTION IN SACCHAROMYCES-CEREVISIAE
ALTERATIONS IN THE ADENINE-PLUS-THYMINE-RICH REGION OF CEN3 AFFECT CENTROMERE FUNCTION IN SACCHAROMYCES-CEREVISIAE
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DOI：
10.1128/mcb.7.1.68
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发表时间：
1987-01-01
影响因子：
5.3
通讯作者：
FITZGERALDHAYES, M
中科院分区：
文献类型：
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作者：
GAUDET, A;FITZGERALDHAYES, M
对酿酒酵母16条染色体中11条的着丝粒DNA进行了分析，发现了每个着丝粒共有的三个序列元件，称为保守着丝粒DNA元件（CDE）。富含腺嘌呤加胸腺嘧啶（A + T）的核心元件CDE II，两侧有两个短的保守序列，CDE I（8个碱基对[bp]）和CDE III （25 bp）。虽然不同CDE II区域之间没有一致的序列，但它们在序列组织上有三个共同的特征。第一，CDE II的区域长度相似，从CDE I到CDE III的左边界，长度在78 ~ 86 bp之间。其次，碱基组成总是大于90% A + T。最后，这些片段中的A和T残基往往排成A串和T串，有时一段有6到7个碱基。我们在染色体III （CEN3）的着丝粒CDE II区域构建了插入、缺失和替换突变，旨在研究着丝粒CDE II区域功能的长度和序列要求。我们分析了这些改变的着丝粒对酿酒酵母质粒和染色体分离的影响。我们的研究结果表明，将CDE II的长度从84 bp增加到154 bp会导致染色体不分离增加10倍。去除富含A + r的CDE II DNA片段的缺失突变也会导致异常分离。在某些情况下，可以通过用与野生型CDE II DNA的初级序列或碱基组成非常不同的片段替换缺失的DNA来恢复部分功能。此外，我们发现在CDE II中引入不同位置的相同突变具有非常相似的效果。
Centromere DNA from 11 of the 16 chromosomes of the yeast Saccharomyces cerevisiae have been analyzed and reveal three sequence elements common to each centromere, referred to as conserved centromere DNA elements (CDE). The adenine-plus-thymine (A + T)-rich central core element, CDE II, is flanked by two short conserved sequences, CDE I (8 base pairs [bp]) and CDE III (25 bp). Although no consensus sequence existed among the different CDE II regions, they do have three common features of sequence organization. First, the CDE II regions are similar in length, ranging from 78 to 86 bp measured from CDE I to the left boundary of CDE III. Second, the base composition is always greater than 90% A + T. Finally, the A and T residues in these segments are often arranged in runs of A and runs of T residues, sometimes with six or seven bases in a stretch. We constructed insertion, deletion and replacement mutations in the CDE II region of the centromere from chromosome III, CEN3, designed to investigate the length and sequence requirements for function of the CDE II region of the centromere. We analyzed the effect of these altered centromeres on plasmid and chromosome segregation in S. cerevisiae. Our results show that increasing the length of CDE II from 84 to 154 bp causes a 10-fold increase in chromosome nondisjunction. Deletion mutations removing segments of the A + R-rich CDE II DNA also cause aberrant segregation. In some cases partial function could be restored by replacing the deleted DNA with fragments whose primary sequence or base composition is very different from that of the wild-type CDE II DNA. In addition, we found that identical mutation introduced into different positions in CDE II have very similar effects.