Related Experiment Video
Updated: Jul 10, 2026
06:59
Nanomanipulation of Single RNA Molecules by Optical Tweezers
Published on: August 20, 2014
Slight sequence modifications unexpectedly alter the metal-dependency of a kissing-loop interaction
Shoji P Ohuchi1, Yoshikazu Nakamura
1Department of Basic Medical Sciences, Insutitute of Medical Science, University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639, Japan.
Nucleic Acids Symposium Series (2004)
|November 22, 2007
Summary
Researchers discovered a novel kissing-loop RNA motif that binds HIV-1 TAR RNA. Divalent cation dependency revealed complex roles for metal ions in simple RNA structures, impacting biological processes.
Area of Science:
- Molecular Biology
- Biochemistry
- RNA Structure and Function
Background:
- Kissing-loop RNA-RNA interactions are crucial for various biological functions.
- The HIV-1 transactivation responsible (TAR) RNA is a key regulatory element in viral replication.
Purpose of the Study:
- To identify and characterize novel RNA motifs involved in kissing-loop interactions.
- To investigate the binding of a new kissing-loop RNA motif to HIV-1 TAR RNA.
- To analyze the role of divalent cations in these RNA-RNA interactions.
Main Methods:
- Modified Systematic Evolution of Ligands by EXponential enrichment (SELEX) procedure to isolate RNA motifs.
- Surface Plasmon Resonance (SPR) analysis to quantify binding kinetics and affinity.
- Comparative analysis of divalent cation dependency for different RNA motifs.
Main Results:
- A novel kissing-loop RNA motif capable of binding HIV-1 TAR RNA was successfully obtained.
- SPR analyses revealed distinct divalent cation dependencies for the newly identified motif compared to previously reported ones.
- The study highlights unexpected variations in metal ion requirements even for simple RNA structures.
Conclusions:
- The identified kissing-loop RNA motif represents a new player in RNA-RNA interactions.
- Divalent cations play intricate and structure-dependent roles in mediating RNA-RNA binding.
- Understanding these complex metal ion roles is essential for deciphering RNA function in biological systems.
More Related Videos
Related Concept Videos
01:27Biasing of Metal-Semiconductor Junctions
Biasing metal-semiconductor junctions involves applying a voltage across the junction. Specifically, the metal is connected to a voltage source, while the semiconductor is grounded. This technique is essential for controlling the direction and magnitude of current flow in electronic devices, including diodes, transistors, and photovoltaic cells.
In Schottky junctions, where the semiconductor is n-type, applying a positive voltage to the metal relative to the semiconductor reduces its Fermi...
In Schottky junctions, where the semiconductor is n-type, applying a positive voltage to the metal relative to the semiconductor reduces its Fermi...
02:51Metal-Ligand Bonds
The hemoglobin in the blood, the chlorophyll in green plants, vitamin B-12, and the catalyst used in the manufacture of polyethylene all contain coordination compounds. Ions of the metals, especially the transition metals, are likely to form complexes.
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
01:19Complexation Equilibria: The Chelate Effect
In complexation reactions, metal atoms or cations interact with ligands to form donor-acceptor adducts called metal complexes. Ligands that bind through one donor site are monodentate, ligands with two donor sites are bidentate, and those with more than two donor sites are polydentate ligands. For example, ethylene diamine is a bidentate ligand that binds through two nitrogen donor atoms, forming a five-membered ring. EDTA is a polydentate ligand that binds through four oxygen and two nitrogen...
02:32Bonding in Metals
Metallic bonds are formed between two metal atoms. A simplified model to describe metallic bonding has been developed by Paul Drüde called the “Electron Sea Model”.
01:09Complexation 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...
01:23Complexation Equilibria: Overview
Complexation reactions take place when dative or coordinate covalent bonds form between metal ions and ligands. The compounds formed in these reactions are called coordination compounds. The number of bonds formed between the metal ion and the ligands is called its coordination number. Generally, most metal ions in an aqueous solution are solvated by water molecules and thus exist as aqua complexes.
The equilibrium constant of the complexation reaction is represented as the formation constant...
The equilibrium constant of the complexation reaction is represented as the formation constant...