确定一个RNA金属离子核心折叠的Mg2+固态度
Rhiju Das1, Kevin J Travers, Yu Bai
1Department of Physics and Biochemistry, Stanford University, Stanford, CA 94305, USA.
Journal of the American Chemical Society
|June 9, 2005
概括
确定RNA折叠所必需的离子数量是一项挑战. 这项研究精确量化了 ribozyme 折叠中的离子固态度,揭示了关键的两离子相互作用.
科学领域:
- 生物化学 生物化学
- 分子生物学分子生物学
- 结构生物学 结构生物学
背景情况:
- RNA折叠和催化活性严重依赖于二价金属离子,如.
- 准确确定金属离子与RNA结合的固态度是一个重大挑战.
- 以前的方法,例如解释希尔系数,受到分散的离子大气和复杂的折叠路径的限制.
研究的目的:
- 为了精确确定离子所涉及的离子的固态度,在P4-P6域的折叠中参与了Tetrahymena I组的 ribozyme.
- 通过使用特定的解决条件来克服以前方法的局限性.
- 提供金属离子结合和RNA折叠之间的合的基本理解.
主要方法:
- 使用高度的背景单价盐来简化溶液条件.
- 将希尔分析应用于基足迹数据.
- 采用光定位和原子辐射光谱来直接计算结合的离子.
主要成果:
- 发现P4-P6RNA核心在正确的两个离子的结合后会合作折叠.
- 这种意想不到的低静脉测量通过多种独立的技术得到了验证.
- 该研究精确量化了与特定RNA状态结合的离子的数量.
结论:
- 离子结合的精确固化计对于理解RNA折叠和功能至关重要.
- 这项工作建立了一种可靠的方法,用于确定RNA中的金属离子静态度.
- 这些发现为RNA-金属离子相互作用的热力学分析提供了一个关键的缺失部分.
更多相关视频
14:44Structure and Coordination Determination of Peptide-metal Complexes Using 1D and 2D 1H NMR
Published on: December 16, 2013
11:04Ion Mobility-Mass Spectrometry Techniques for Determining the Structure and Mechanisms of Metal Ion Recognition and Redox Activity of Metal Binding Oligopeptides
Published on: September 7, 2019
相关概念视频
RNA Stability
Intact DNA strands can be found in fossils, while scientists sometimes struggle to keep RNA intact under laboratory conditions. The structural variations between RNA and DNA underlie the differences in their stability and longevity. Because DNA is double-stranded, it is inherently more stable. The single-stranded structure of RNA is less stable but also more flexible and can form weak internal bonds. Additionally, most RNAs in the cell are relatively short, while DNA can be up to 250 million...
Valence Bond Theory
Coordination compounds and complexes exhibit different colors, geometries, and magnetic behavior, depending on the metal atom/ion and ligands from which they are composed. In an attempt to explain the bonding and structure of coordination complexes, Linus Pauling proposed the valence bond theory, or VBT, using the concepts of hybridization and the overlapping of the atomic orbitals. According to VBT, the central metal atom or ion (Lewis acid) hybridizes to provide empty orbitals of suitable...
Colors and Magnetism
Color in Coordination Complexes
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human eye.
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human eye.
RNA Stability
Intact DNA strands can be found in fossils, while scientists sometimes struggle to keep RNA intact under laboratory conditions. The structural variations between RNA and DNA underlie the differences in their stability and longevity. Because DNA is double-stranded, it is inherently more stable. The single-stranded structure of RNA is less stable but also more flexible and can form weak internal bonds. Additionally, most RNAs in the cell are relatively short, while DNA can be up to 250 million...
Atomic Nuclei: Nuclear Magnetic Moment
All atomic nuclei are positively charged. When they have a nonzero spin, they behave like rotating charges. As a consequence of their charge and spin, these nuclei generate a magnetic field (B). This, in turn, gives rise to a magnetic moment (μ), which is randomly oriented in the absence of an external magnetic field. When an external magnetic field (B0) is applied, the magnetic moment vectors can align with the field or against it in 2 + 1 orientations. A hydrogen nucleus, which is just a...
Complexation Equilibria: Factors Influencing Stability of Complexes
In complexation reactions, metal cations are the electron pair acceptors, and the ligands are the electron pair donors. The stability of the metal complexes depends primarily on the complexing ability of the central metal ion and the nature of the ligands. Generally, the complexing ability of the metal ion depends on the size and charge of the ion. As the metal ion size increases, the stability of the metal complexes decreases, provided that the valency of the metal ion and the ligands remain...
