Structural Biology of XPB and XPD Helicases

XPB 和 XPD 解旋酶的结构生物学

• 批准号: 7388307
• 负责人: John A. Tainer
• 金额: $ 29.84万
• 依托单位: UNIVERSITY OF CALIF-LAWRENC BERKELEY LAB
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-04-01 至 2011-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7388307
• 关键词: ATP phosphohydrolase; Architecture; Biochemical; Biochemistry; Biological; Biological Process; Biophysics; Cell Death; Cockayne Syndrome; Complex; DNA; DNA Damage; DNA Repair; Defect; Disease; Disruption; ERCC2 gene; ERCC3 gene; ERCC5 gene; Electrons; Eukaryota; Eukaryotic Cell; Event; Figs - dietary; Gene Mutation; Genetic Transcription; Germ-Line Mutation; Homologous Gene; Human; In Vitro; Inherited; Knowledge; Laboratories; Lead; Length; Link; Malignant Neoplasms; Maps; Mediating; Mental Retardation; Microscopic; Molecular; Molecular Conformation; Molecular Structure; Mutation; Nerve Degeneration; Nucleotide Excision Repair; Outcome; Pathway interactions; Patients; Personal Satisfaction; Phenotype; Predisposition; Premature aging syndrome; Process; Proteins; Repair Complex; Resolution; Role; Skin Cancer; Specificity; Structure; Structure-Activity Relationship; Syndrome; Testing; Transcription Initiation; Transcription-Coupled Repair; Trichothiodystrophy; XPGC protein; Xeroderma Pigmentosum; base; cancer cell; clinical phenotype; disease phenotype; disease-causing mutation; helicase; human disease; in vivo; mutant; protein protein interaction; repaired; research study; structural biology; transcription factor TFIIH

Hereditary mutations in the DNA helicases XPB and XPD lead to human diseases with different phenotypes reflecting increased cancers or increased cell death: xeroderma pigmentosum (XP), XP- linked Cockayne syndrome (CS), and trichothiodystrophy (TTD). These diseases reflect the disruption of different cellular pathways: Defective nucleotide-excision repair (NER) results in XP, perturbed transcription-coupled repair (TCR) leads to CS, and transcription abnormalities combined with defective NER cause TTD. In humans, XPB and XPD helicases are part of the ten subunit TFIIH transcription/repair complex, but disease-causing mutations cluster in XPB and particularly XPD rather than in the other TFIIH proteins, excepting TFB5, so these XP helicases appear key to controlling coordination of transcription and repair. Furthermore, the repair proteins XPG and CSB interact with the XP helicases in TCR. However, there is little knowledge at the molecular level about XPB and XPD, their helicase and repair activities, or their interactions with TFB5, CSB and XPG. We aim to understand the molecular features underlying the specificity, activity, conformational controls and pathway coordination by the XPB and XPD helicases. Our hypothesis is that well-defined architectures, conformational states, and molecular interfaces of XPB and XPD helicases provide critical controls for transcription, NER, and TCR. We furthermore propose that characterizations of these features and their disruption by disease-causing mutations will provide a molecular basis to directly connect the inherited gene mutations to disease phenotypes. To test this, we herein propose to integrate structural and biophysical experiments (Tainer laboratory) with biochemical and biological experiments (Cooper laboratory). Our experiments on XPB and XPD domains and full-length proteins, their archaeal homologues, and their key assemblies will establish molecular architectures, conformational switching mechanisms, and allosteric interactions. We expect to characterize a prototypical set of helicase structures, their complexes with DNA and with protein partners, and to define the key interactions for their activities. The anticipated outcome of the proposed cross-disciplinary experiments is a molecular picture of the protein-DNA complexes, protein-protein interactions and functional states that orchestrate transcription and repair events mediated by XPB and XPD as components of TFIIH. These results will help provide a detailed molecular understanding of the processes that underlie the cancer and cell death disease phenotypes associated with XPB, XPD, TFB5, CSB and XPG patient mutations.

DNA解旋酶XPB和XPD中的遗传突变导致人类疾病不同 反映癌症增加或细胞死亡增加的表型：心虫色素（XP），XP- 连接的Cockayne综合征（CS）和Trichothiodyrophophy（TTD）。这些疾病反映了 不同的细胞途径：有缺陷的核苷酸 - 分离修复（NER）导致XP扰动 转录耦合修复（TCR）导致CS，转录异常与缺陷相结合 ner原因TTD。在人类中，XPB和XPD解旋酶是十个亚基TFIIH的一部分 转录/修复复合物，但引起疾病的突变群集在XPB中，尤其是XPD而不是 除了TFB5以外 转录和修复的协调。此外，修复蛋白XPG和CSB与 TCR中的XP解旋酶。但是，关于XPB和XPD的分子水平上几乎没有知识， 它们的解旋酶和维修活动，或与TFB5，CSB和XPG的相互作用。我们的目标 了解特异性，活性，构象控制和 XPB和XPD解放酶的途径协调。我们的假设是定义明确的架构， XPB和XPD解旋酶的构象状态以及分子界面为关键控制提供 转录，NER和TCR。我们进一步提出了这些特征及其它们的特征 引起疾病突变的破坏将提供分子基础，直接连接遗传 疾病表型的基因突变。为了测试这一点，我们在此提议将结构和 生化和生物学实验的生物物理实验（Tainer实验室）（库珀 实验室）。我们对XPB和XPD域以及全长蛋白的实验，其古细菌 同源物及其关键组件将建立分子体系结构，构象切换 机制和变构相互作用。我们期望表征一组原型的解旋酶 结构，与DNA和蛋白质伴侣的复合物，并定义 他们的活动。提出的跨学科实验的预期结果是分子 蛋白-DNA复合物，蛋白质 - 蛋白质相互作用和编排的功能状态的图片 XPB和XPD介导的转录和修复事件作为TFIIH的组成部分。这些结果将会 帮助提供对癌症和细胞基础的过程的详细分子理解 与XPB，XPD，TFB5，CSB和XPG患者突变有关的死亡疾病表型。