SAF-Box, a conserved protein domain that specifically recognizes scaffold attachment region DNA
SAF-Box, a conserved protein domain that specifically recognizes scaffold attachment region DNA
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DOI：
10.1128/mcb.20.20.7480-7489.2000
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发表时间：
2000-10-01
影响因子：
5.3
通讯作者：
Fackelmayer, FO
中科院分区：
文献类型：
--
作者：
Kipp, M;Göhring, F;Fackelmayer, FO
SAR（scaffold attachment regions）是通过将DNA连接到核支架或基质的蛋白质上而将真核生物基因组分割成独立的染色质环的候选DNA元件。SAR与核支架的相互作用在进化上是保守的，并且似乎是由于特异性DNA结合蛋白通过尚不清楚的机制识别SAR。我们描述了一种新的，进化上保守的蛋白质结构域，特异性结合SAR，但不相关的SAR结合基序的其他蛋白质。该结构域首先在人支架附着因子A（SAF-A）中被鉴定，因此被命名为SAF-Box。SAF盒存在于从酵母到人类起源的许多不同蛋白质中，并且似乎在结构上与同源结构域相关。我们在这里展示了来自四个不同来源的SAF盒以及合成的SAF盒肽，以高特异性结合天然和人工SAR。特异性SAR结合的新结构域是通过一个不寻常的质量结合模式，是敏感的偏端霉素，但不色霉素，并显示出明显的偏好长的DNA片段。这是第一次表征的特定SAR结合域，是保守的整个进化过程中，并具有DNA结合特性，非常类似的未分级的核支架。
SARs (scaffold attachment regions) are candidate DNA elements for partitioning eukaryotic genomes into independent chromatin loops by attaching DNA to proteins of a nuclear scaffold or matrix. The interaction of SARs with the nuclear scaffold is evolutionarily conserved and appears to be due to specific DNA binding proteins that recognize SARs by a mechanism not yet understood. We describe a novel, evolutionarily conserved protein domain that specifically binds to SARs but is not related to SAR binding motifs of other proteins. This domain was first identified in human scaffold attachment factor A (SAF-A) and was thus designated SAF-Box. The SAF-Box is present in many different proteins ranging from yeast to human in origin and appears to be structurally related to a homeodomain. We show here that SAF-Boxes from four different origins, as well as a synthetic SAF-Box peptide, bind to natural and artificial SARs with high specificity. Specific SAR binding of the novel domain is achieved by an unusual mass binding mode, is sensitive to distamycin but not to chromomycin, and displays a clear preference for long DNA fragments. This is the first characterization of a specific SAR binding domain that is conserved throughout evolution and has DNA binding properties that closely resemble that of the unfractionated nuclear scaffold.