TRYPANOSOMA BRUCEI ARGINASE-LIKE PROTEIN

布氏锥虫精氨酸酶样蛋白

• 批准号: 8363354
• 负责人: Lakshmi Sangeetha Vedula
• 金额: $ 0.4万
• 依托单位: BROOKHAVEN SCIENCE ASSOC-BROOKHAVEN LAB
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-07-01 至 2012-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8363354
• 关键词: Acetylation; American Public Health Association; Amino Acid Substitution; Binding; Binding Sites; Catalysis; Complex; Crystallography; Data; Enzymes; Eukaryotic Cell; Family; Funding; Grant; Histones; Hydrogen Bonding; Isoenzymes; Ligands; Light; Lysine; Metals; National Center for Research Resources; Potassium; Principal Investigator; Proteins; Reporting; Research; Research Infrastructure; Resolution; Resources; Source; Structure; Structure-Activity Relationship; Synchrotrons; System; Trichostatin A; Trypanosoma brucei brucei; United States National Institutes of Health; Variant; Work; arginase; cost; hydroxamate; member; monomer; mutant

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Metal-dependent histone deacetylases (HDACs) require Zn2+ or Fe2+ to regulate the acetylation of lysine residues in histones and other proteins in eukaryotic cells. The HDAC8 isozyme is perhaps the archetypical member of the class I HDAC family and represents the paradigm for understanding structure-activity relationships in this enzyme family. Here, we report the structures of HDAC8 complexes with trichostatin A and 3-(1-methyl-4-phenylacetyl-1H-2-pyrrolyl)-N-hydroxy-2-propenamide (APHA) in a new crystal form. The structure of the APHA complex reveals that the hydroxamate C=O group does not coordinate to Zn2+ with favorable geometry, perhaps due to the constraints of its extended ? system, but instead accepts a hydrogen bond from Y306. Additionally, since APHA binds to only 2 of the 3 protein molecules in the asymmetric unit of this complex, the structure of the third monomer represents the first structure of HDAC8 in the unliganded state. Comparison of unliganded and liganded structures illustrates ligand-induced conformational changes in the L2 loop that likely accompany substrate binding and catalysis. Furthermore, these structures, along with those of the D101N, D101E, D101A, and D101L variants, support the proposal that D101 is critical for the function of the L2 loop. However, amino acid substitutions for D101 can also trigger conformational changes of Y111 and W141 that perturb the substrate binding site. We are continuing to work on getting higher resolution data for the D101E mutant, and working to explore potassium binding sites with the HDAC8 enzyme.

该子项目是利用资源的众多研究子项目之一 由 NIH/NCRR 资助的中心拨款提供。子项目的主要支持 并且子项目的主要研究者可能是由其他来源提供的， 包括其他 NIH 来源。 子项目可能列出的总成本 代表子项目使用的中心基础设施的估计数量， NCRR 赠款不直接向子项目或子项目工作人员提供资金。 金属依赖性组蛋白脱乙酰酶 (HDAC) 需要 Zn2+ 或 Fe2+ 来调节真核细胞中组蛋白和其他蛋白质中赖氨酸残基的乙酰化。 HDAC8 同工酶可能是 I 类 HDAC 家族的典型成员，代表了理解该酶家族结构-活性关系的范例。 在这里，我们报道了 HDAC8 与曲古抑菌素 A 和 3-(1-甲基-4-苯乙酰基-1H-2-吡咯基)-N-羟基-2-丙烯酰胺 (APHA) 的新晶型复合物的结构。 APHA配合物的结构表明，异羟肟酸C=O基团不与具有有利几何形状的Zn2+配位，这可能是由于其扩展的？系统，但接受来自 Y306 的氢键。 此外，由于 APHA 仅与该复合物不对称单元中 3 个蛋白质分子中的 2 个结合，因此第三个单体的结构代表了未配体状态下 HDAC8 的第一个结构。 未配体和配体结构的比较表明配体诱导的 L2 环构象变化可能伴随底物结合和催化。 此外，这些结构以及 D101N、D101E、D101A 和 D101L 变体的结构都支持 D101 对于 L2 环路功能至关重要的观点。 然而，D101 的氨基酸取代也会引发 Y111 和 W141 的构象变化，从而扰乱底物结合位点。 我们正在继续努力获取 D101E 突变体的更高分辨率数据，并努力探索 HDAC8 酶的钾结合位点。