Retinoblastoma-binding Protein 1 Has an Interdigitated Double Tudor Domain with DNA Binding Activity*
Retinoblastoma-binding Protein 1 Has an Interdigitated Double Tudor Domain with DNA Binding Activity*
复制标题
视网膜母细胞瘤结合蛋白 1 具有具有 DNA 结合活性的叉指双 Tudor 结构域*
DOI：
10.1074/jbc.m113.501940
复制
发表时间：
2014-02-21
影响因子：
4.8
通讯作者：
Feng, Yingang
中科院分区：
文献类型：
--
作者：
Gong, Weibin;Wang, Jinfeng;Feng, Yingang
背景：视网膜母细胞瘤结合蛋白1 （RBBP1）是一种肿瘤抑制因子，具有功能未知的Tudor结构域。结果：都铎结构域为互指双都铎结构，具有DNA结合活性。结论：RBBP1家族的Tudor结构域是一个DNA结合模块。意义：我们的研究为RBBP1功能和Tudor结构域的多样性提供了进一步的结构见解。视网膜母细胞瘤结合蛋白1 （RBBP1）是一种肿瘤和白血病抑制因子，可结合甲基化组蛋白尾部和DNA。我们之前的研究表明，RBBP1具有Tudor结构域，不能结合组蛋白标记。为了阐明Tudor结构域的功能，通过NMR测定了RBBP1 Tudor结构域的溶液结构，并在此给出。虽然这两种蛋白不相关，但RBBP1都铎结构域与JMJD2A的都铎结构域类似，形成一种交叉的双都铎结构，是一种表观遗传标记读取器。这表明都铎结构域的功能多样性。RBBP1 Tudor结构域具有显著的正电荷表面面积，这表明RBBP1 Tudor结构域具有结合核酸的能力。核磁共振滴定和等温滴定量热实验表明，RBBP1 Tudor结构域与双链和单链DNA均具有10-100 μm的亲和力；未发现明显的DNA序列特异性。利用核磁共振数据，通过HADDOCK对接构建Tudor结构域- dsdna复合物模型结构，详细分析了DNA结合模式和关键相互作用残基。静电相互作用介导都铎结构域与DNA的结合，这与高盐浓度下进行的核磁共振实验一致。dna结合残基在RBBP1蛋白家族的Tudor结构域中是保守的，导致RBBP1 Tudor结构域中的dna结合功能是保守的。我们的研究结果为RBBP1的结构和功能提供了进一步的见解。
Background: Retinoblastoma-binding protein 1 (RBBP1), a tumor suppressor, has a Tudor domain with unknown function. Results: The Tudor domain adopts an interdigitated double Tudor structure with DNA binding activity. Conclusion: The Tudor domain of the RBBP1 family is a DNA binding module. Significance: Our research provides further structural insights into RBBP1 function and the diversity of Tudor domains. Retinoblastoma-binding protein 1 (RBBP1) is a tumor and leukemia suppressor that binds both methylated histone tails and DNA. Our previous studies indicated that RBBP1 possesses a Tudor domain, which cannot bind histone marks. In order to clarify the function of the Tudor domain, the solution structure of the RBBP1 Tudor domain was determined by NMR and is presented here. Although the proteins are unrelated, the RBBP1 Tudor domain forms an interdigitated double Tudor structure similar to the Tudor domain of JMJD2A, which is an epigenetic mark reader. This indicates the functional diversity of Tudor domains. The RBBP1 Tudor domain structure has a significant area of positively charged surface, which reveals a capability of the RBBP1 Tudor domain to bind nucleic acids. NMR titration and isothermal titration calorimetry experiments indicate that the RBBP1 Tudor domain binds both double- and single-stranded DNA with an affinity of 10–100 μm; no apparent DNA sequence specificity was detected. The DNA binding mode and key interaction residues were analyzed in detail based on a model structure of the Tudor domain-dsDNA complex, built by HADDOCK docking using the NMR data. Electrostatic interactions mediate the binding of the Tudor domain with DNA, which is consistent with NMR experiments performed at high salt concentration. The DNA-binding residues are conserved in Tudor domains of the RBBP1 protein family, resulting in conservation of the DNA-binding function in the RBBP1 Tudor domains. Our results provide further insights into the structure and function of RBBP1.