A TISSUE-SPECIFIC MAR/SAR DNA-BINDING PROTEIN WITH UNUSUAL BINDING-SITE RECOGNITION
A TISSUE-SPECIFIC MAR/SAR DNA-BINDING PROTEIN WITH UNUSUAL BINDING-SITE RECOGNITION
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DOI：
10.1016/0092-8674(92)90432-c
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发表时间：
1992-08-21
期刊：
影响因子：
64.5
通讯作者：
KOHWISHIGEMATSU, T
中科院分区：
文献类型：
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作者：
DICKINSON, LA;JOH, T;KOHWISHIGEMATSU, T
克隆了一个编码DNA结合蛋白(SATB1)的人基因，该蛋白主要在胸腺中表达，并选择性地与核基质/支架相关DNA(MARS/SARS)结合。缺失核苷实验表明，SATB1选择性地结合在一个特殊的富含AT的序列环境中，其中一条链由混合的A、T和C组成，不包括G(ATC序列)。当这一特征被突变破坏时，即使直接接触序列保持完整，SATB1结合也会大大减少。在超螺旋DNA中，连接的SATB1结合序列变得稳定地不配对。降低解离潜力的特定突变极大地减少了SATB1的结合。然而，SATB1不与单链DNA结合。化学干扰分析表明，SATB1沿着小槽结合，与碱基接触很少。这表明SATB1通过双链DNA中存在的改变的糖-磷酸骨架结构间接识别ATC序列。
A human cDNA was cloned that encodes a DNA-binding protein (SATB1) that is expressed predominantly in thymus and binds selectively to the nuclear matrix/scaffold-associating DNAs (MARs/SARs). Missing nucleoside experiments showed that SATB1 selectively binds in a special AT-rich sequence context where one strand consists of mixed A's, T's, and C's, excluding G's (ATC sequences). When this feature is destroyed by mutation, SATB1 binding is greatly reduced even if the direct contact sequence remains intact. Conjunctional SATB1-binding sequences become stably unpaired in supercoiled DNA. Specific mutations that diminish the unwinding potential greatly reduce SATB1 binding. However, SATB1 does not bind single-stranded DNA. Chemical interference assays show that SATB1 binds along the minor groove with very little contact with the bases. This suggests that SATB1 recognizes the ATC sequence indirectly through the altered sugar-phosphate backbone structure present in the double-stranded DNA.