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Updated: Jul 7, 2026
12:07
Sequence-specific Labeling of Nucleic Acids and Proteins with Methyltransferases and Cofactor Analogues
Published on: November 22, 2014
Adenosyltransferase tailors and delivers coenzyme B12
Dominique Padovani1, Tetyana Labunska, Bruce A Palfey
1Biological Chemistry Department, University of Michigan, 1150 West Medical Center Drive, Ann Arbor, Michigan 48109-0606, USA.
Nature Chemical Biology
|February 12, 2008
Summary
Cofactor delivery to enzymes is challenging. Adenosyltransferase directly transfers coenzyme B12 to methylmalonyl coenzyme A mutase, suggesting a general cofactor trafficking strategy.
Area of Science:
- Biochemistry
- Enzymology
- Molecular Biology
Background:
- Cofactors are essential for enzyme function but their delivery to target enzymes is often hindered by reactivity and rarity.
- Coenzyme B12 is a vital cofactor involved in numerous metabolic pathways.
Purpose of the Study:
- To investigate the mechanism of coenzyme B12 delivery to methylmalonyl coenzyme A mutase.
- To explore the role of adenosyltransferase in cofactor trafficking.
Main Methods:
- Kinetic analyses were employed to study the interaction between adenosyltransferase and methylmalonyl coenzyme A mutase.
- Enzyme assays were performed to quantify reaction rates and cofactor transfer efficiency.
Main Results:
- Adenosyltransferase was found to directly transfer coenzyme B12 to methylmalonyl coenzyme A mutase.
- The kinetic data support a direct cofactor transfer mechanism, bypassing free cofactor diffusion.
Conclusions:
- The final enzyme in a cofactor assimilation pathway can play a direct role in delivering the cofactor to its target enzyme.
- This direct transfer strategy represents a potentially general mechanism for cofactor trafficking in biological systems.
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