Structural Biology of XPB and XPD Helicases

XPB 和 XPD 解旋酶的结构生物学

• 批准号: 8212285
• 负责人: John A. Tainer
• 金额: $ 32.82万
• 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 2015-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8212285
• 关键词: Address; Aging; Amino Acids; Architecture; Back; Binding; Biochemical; Biological; Biology; Blinded; Cell Death; Chemistry; Child; Clinic; Cockayne Syndrome; Code; Complex; DNA; DNA Damage; DNA Repair; DNA Structure; Defect; Disease; ERCC3 gene; Employee Strikes; Event; Future; Gene Mutation; Genes; Genetic Code; Genetic Transcription; Germ-Line Mutation; Goals; Grant; Health; Homologous Gene; Human; Inherited; Iron; Lead; Letters; Malignant Neoplasms; Mediating; Modeling; Molecular; Molecular Conformation; Moon; Mutation; Names; Nature; Neurologic; Nucleotide Excision Repair; Nucleotides; Outcome; Oxidation-Reduction; Pathway interactions; Patients; Phenotype; Play; Predisposition; Premature aging syndrome; Process; Proteins; RNA Polymerase II; Repair Complex; Research; Resolution; Role; Skin Cancer; Solutions; Specificity; Structural Biochemistry; Structure; Sulfur; Testing; The Sun; Therapeutic; Transcription-Coupled Repair; Trichothiodystrophy; Xeroderma Pigmentosum; base; cancer cell; cancer risk; clinical phenotype; cofactor; disease phenotype; disease-causing mutation; flexibility; helicase; human disease; insight; member; mutant; protein protein interaction; repaired; research study; stem; structural biology; transcription factor TFIIH

DESCRIPTION (provided by applicant): Hereditary mutations in the DNA helicases XPB and XPD lead to human diseases with different phenotypes reflecting increased cancers or aging: xeroderma pigmentosum (XP), XP combined with Cockayne syndrome (CS), and trichothiodystrophy (TTD). These diseases reflect the disruption of different cellular pathways: nucleotide-excision repair (NER), transcription-coupled repair (TCR), or transcription. 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. 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 have shown that characterizations of these features and their disruption by disease-causing mutations provide a molecular basis to directly connect the inherited gene mutations to disease phenotypes. Building on our crystal structures of XPB and XPD, we propose to integrate structural and biophysical experiments including small angle x-ray scattering to define conformations and complexes in solution with biochemical and biological experiments to determine structures of disease-relevant mutants, protein-DNA complexes, and define 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 XP, XP/CS, and TTD patient mutations.

描述（由申请人提供）：DNA解旋酶XPB和XPD中的遗传突变导致具有不同表型的人类疾病，反映了癌症或衰老的增加：着色性干皮病（XP）、XP合并Cockayne综合征（CS）和甲状腺营养不良（TTD）。这些疾病反映了不同细胞途径的破坏：核苷酸切除修复（NER），转录偶联修复（TCR）或转录。在人类中，XPB和XPD解旋酶是十个亚基TFIIH转录/修复复合物的一部分，但致病突变聚集在XPB中，特别是XPD中，而不是在除TFB 5之外的其他TFIIH蛋白中，因此这些XP解旋酶似乎是控制转录和修复协调的关键。我们的目的是了解潜在的特异性，活性，构象控制和途径协调的XPB和XPD解旋酶的分子特征。我们的假设是，明确定义的架构，构象状态，和XPB和XPD解旋酶的分子界面提供了关键的控制转录，NER和TCR。我们已经表明，这些特征的表征和致病突变对它们的破坏提供了直接将遗传基因突变与疾病表型联系起来的分子基础。在我们的XPB和XPD晶体结构的基础上，我们建议整合结构和生物物理实验，包括小角X射线散射，以定义溶液中的构象和复合物，并进行生化和生物实验，以确定疾病相关突变体、蛋白质的结构-DNA复合物，并定义其活性的关键相互作用。所提出的跨学科实验的预期结果是蛋白质-DNA复合物、蛋白质-蛋白质相互作用和功能状态的分子图像，所述功能状态协调由XPB和XPD作为TFIIH的组分介导的转录和修复事件。这些结果将有助于提供一个详细的分子理解的过程，基础上的癌症和细胞死亡疾病的表型与XP，XP/CS和TTD患者突变。