Malachite green RNA aptamer (MG aptamer) (MG aptamer)

The Malachite green RNA aptamer is a synthetic RNA sequence identified through Systematic Evolution of Ligands by Exponential Enrichment (SELEX) for its ability to bind the triphenylmethane dye malachite green with high specificity (Grate and Wilson, 1999). This aptamer is not a naturally occurring biological receptor but serves as a powerful tool in molecular biology and synthetic biology. Upon binding its ligand, the aptamer constrains the dye's structure, preventing the rotation of its phenyl rings and thereby increasing its fluorescence quantum yield by approximately 1000-fold (Baugh et al., 2000). This unique property allows the aptamer to function as a fluorogenic tag for monitoring RNA transcription, localization, and folding in real-time within cellular environments (Babendure et al., 2003). While it is highly effective as a biosensor, the use of the malachite green aptamer in live organisms is often limited by the inherent toxicity and potential carcinogenicity of the malachite green dye itself (Srivastava et al., 2004). Consequently, it is primarily used in in vitro assays or specialized imaging applications rather than as a target for therapeutic intervention.

Other names

Malachite green-binding RNA aptamerMG-binding aptamerMGA

The aptamer binds the malachite green ligand within a specific binding pocket, restricting its internal molecular rotation and thereby activating its fluorescence, which is otherwise quenched in solution (Baugh et al., 2000).