Riboswitch effectors as protein enzyme cofactors

Area of Science:

• Biochemistry
• Molecular Biology
• Origin of Life Studies

Background:

• The glmS ribozyme demonstrates RNA enzymes can utilize small molecules as catalytic cofactors.
• Key cofactors like flavin mononucleotide (FMN), S-adenosyl methionine (SAM), adenosyl cobalamin (AdoCbl), and thiamine pyrophosphate (TPP) are known RNA riboswitch ligands and potent protein enzyme cofactors.
• Expanding ribozyme capabilities to harness cofactor chemical potential could broaden their enzymatic repertoire.

Purpose of the Study:

• To review the chemistry of AdoCbl, SAM, FMN, and TPP in protein enzymology.
• To speculate on the potential use of these cofactors by ribozymes in the prebiotic RNA World.
• To consider potential applications of cofactor-harnessing ribozymes in modern biology.

Main Methods:

• Literature review of cofactor chemistry in protein enzymology.
• Analysis of known ribozyme structures and functions.
• Speculative modeling of ribozyme-cofactor interactions.

Main Results:

• Detailed overview of the catalytic roles of AdoCbl, SAM, FMN, and TPP in protein enzymes.
• Identification of potential mechanisms for ribozymes to bind and chemically utilize these cofactors.
• Exploration of evolutionary scenarios for cofactor utilization in the RNA World.

Conclusions:

• RNA enzymes have the potential to evolve sophisticated catalytic functions by harnessing small molecule cofactors.
• The chemical versatility of cofactors suggests a broader scope for ribozyme activity than previously appreciated.
• Cofactor-utilizing ribozymes may offer novel tools for synthetic biology and understanding early life evolution.