Interaction of hepatitis B virus X protein with damaged DNA-binding protein p 127: Structural analysis and identification of antagonists
Interaction of hepatitis B virus X protein with damaged DNA-binding protein p 127: Structural analysis and identification of antagonists
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DOI：
10.1159/000067287
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发表时间：
2002-11-01
影响因子：
11
通讯作者：
Transy, C
中科院分区：
文献类型：
--
作者：
Bergametti, F;Bianchi, J;Transy, C
乙型肝炎病毒X蛋白是一种多功能蛋白，对自然感染至关重要，也与肝癌的发展有关。先前的研究已经确定受损dna结合复合体的DDB1亚基在感染过程中是X蛋白的关键伙伴，X介导的细胞毒性和病毒蛋白的稳定性。在这里，我们使用各种突变分析研究了X-DDB1相互作用的结构和功能约束。我们的数据表明，X与DDB1的相互作用界面仅限于15个残基表位。所有导致失去结合的替换都映射到这个核心结合域。相反，对DDB1亲和力的显著增加是由于靠近DDB1结合表位的簇状位置的取代，并与凋亡电位的丧失相关。选择DDB1中部分修复X突变体结合缺陷的突变，进一步了解了这两种蛋白之间建立的联系。重要的是，X的核心结合结构域和获得亲和力的X突变体都抑制了ddb1介导的野生型X蛋白的稳定。因此，这些X蛋白衍生物为开发通过竞争性抑制X- ddb1相互作用来拮抗X功能的治疗剂提供了基础。版权所有(C) 2002中华民国国家科学委员会和S. Karger AG，巴塞尔。
The hepatitis B virus X protein is a multifunctional protein that is essential for natural infection and has also been implicated in liver cancer development. Previous studies have identified the DDB1 subunit of the damaged-DNA binding complex as a critical partner of X protein in the infection process, X-mediated cytotoxicity and stability of the viral protein. Here, we investigated the structural and functional constraints of X-DDB1 interaction using various mutational analyses. Our data show that the interaction interface of X with DDB1 is confined to a 15-residue epitope. All substitutions responsible for loss of binding mapped to this core-binding domain. In contrast, a marked increase in affinity for DDB1 resulted from substitutions at clustered positions lying close to the DDB1-binding epitope and correlated with loss of apoptotic potential. Selection of mutations in DDB1 that partially rescue the binding defect of an X mutant gave further insight into the contacts established between the two proteins. Importantly, both the core-binding domain of X and the gain-of-affinity X mutants inhibited DDB1-mediated stabilization of wild-type X protein. These X protein derivatives thus provide the basis for the development of therapeutic agents that antagonize X function through competitive inhibition of X-DDB1 interaction. Copyright (C) 2002 National Science Council, ROC and S. Karger AG, Basel.