FOLDING OF AN IMMOBILE DNA BRANCHED JUNCTION

固定 DNA 分支连接的折叠

• 批准号: 6205712
• 负责人: NADRIAN C. SEEMAN
• 金额: --
• 依托单位: ALBERT EINSTEIN COLLEGE OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-09-01 至 2000-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6205712
• 关键词: biological products; biomedical resource; biotechnology; enzymes; growth /development; nucleic acids; proteins; radiology; spectrometry; technology /technique

Many macromolecular folding reactions, such as the Mg2+-dependent folding of the Tetrahymena thermophila group I intron, occur on timescales ranging from milliseconds to minutes. Kinetic progress curves describing the millisecond folding of P4-P6 and other domains within the L-21 ribozyme have been obtained using a new OH footprinting technique, stopped-flow synchrotron x-ray footprinting. The folding of P4-P6 is a highly concerted reaction; the regions of OH protection within the interior of the folded domain appear at rates of ? 1.0 sec-1. OH protections within the P5c sub-domain appear at rates of ~ 2.0 sec-1, suggesting that folding of this subdomain is the initial step in the folding pathway. The rates of OH protection of the triple helix junction between P4-P6 and the P3-P7 domain and those protections in P4-P6 ascribed to interaction with the P9 domain at rates of ~ 0.3 sec-1. These results suggest that these tertiary interactions guide the folding of the catalytic core against an extensively folded P4-P6 domain. To further dissect the folding mechanism of the Tetrahymena ribozyme, which we have solved in detail for a single set of conditions, the magnesium and temperature dependence of the folding mechanism will be explored in order to correlate the changes in energetics and structure that occur along the folding pathway.

许多大分子折叠反应，例如mg2+依赖性 四心hymena hythophila i组内含子的折叠发生在 时间尺度从毫秒到几分钟。 动力学进步 描述P4-P6和其他域的毫秒折叠的曲线 在L-21核酶内已使用新的OH获得 足迹技术，停止流量同步器X射线足迹。 P4-P6的折叠是一个高度协调的反应。区域 哦，折叠域内的保护 费率？ 1.0秒-1。 OH P5C子域内的保护 以〜2.0 sec-1的速度出现，表明折叠 子域是折叠路径中的第一步。 费率 OH保护P4-P6和 P3-P7域以及归因于相互作用的P4-P6中的保护 P9域的速率约为0.3秒。 这些结果表明 这些三级相互作用指导催化的折叠 核心与广泛折叠的P4-P6域。 进一步剖析 四氢烷核酶的折叠机理，我们已经有 详细解决了一组条件，镁和 折叠机制的温度依赖性将在 为了关联发生的能量和结构的变化 沿着折叠路径。