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 的遗传性突变会导致具有不同表型的人类疾病，反映癌症或衰老的增加：着色性干皮病 (XP)、XP 合并科凯恩综合征 (CS) 和毛发硫营养不良 (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 10 个亚基 TFIIH 转录/修复复合体的一部分，但致病突变集中在 XPB，特别是 XPD，而不是其他 TFIIH 蛋白（TFB5 除外），因此这些 XP 解旋酶似乎是控制转录和修复协调的关键。我们的目标是了解 XPB 和 XPD 解旋酶的特异性、活性、构象控制和途径协调背后的分子特征。我们的假设是 XPB 和 XPD 解旋酶的明确结构、构象状态和分子界面为转录、NER 和 TCR 提供了关键控制。我们已经证明，这些特征的表征以及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。以 XPB 和 XPD 晶体结构为基础，我们建议将结构和生物物理实验（包括小角度 X 射线散射）与生化和生物实验结合起来，以确定溶液中的构象和复合物，以确定与疾病相关的突变体、蛋白质-DNA 复合物的结构，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景，这些功能状态协调由 XPB 和 XPD 作为 TFIIH 组成部分介导的转录和修复事件。这些结果将有助于提供对与 XP、XP/CS 和 TTD 患者突变相关的癌症和细胞死亡疾病表型背后的过程的详细分子理解。