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A Toolkit to Enable Hydrocarbon Conversion in Aqueous Environments
Published on: October 2, 2012
Origin and evolution of medium chain alcohol dehydrogenases
Hans Jörnvall1, Joel Hedlund, Tomas Bergman
1Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden. Hans.Jornvall@ki.se
Chemico-Biological Interactions
|December 4, 2012
Summary
Alcohol dehydrogenases (ADHs) show distinct superfamily origins, with short-chain (SDR) and medium-chain (MDR) forms appearing early in life's evolution. Their divergence patterns correlate with major global events and evolutionary transitions.
Area of Science:
- Biochemistry
- Evolutionary Biology
- Genomics
Background:
- Alcohol dehydrogenases (ADHs) are crucial enzymes with diverse biological roles.
- Previous studies recognized separate superfamily origins for different ADH lines.
- Recent advancements in genomic databases allow for re-evaluation of these origins.
Purpose of the Study:
- To re-evaluate and extend the understanding of alcohol dehydrogenase superfamily origins using updated databank information.
- To analyze the evolutionary patterns and divergence of short-chain (SDR) and medium-chain (MDR) ADHs.
- To correlate ADH evolutionary events with major geological and biological milestones on Earth.
Main Methods:
- Re-screening of the latest genomic databank updates for ADH sequences.
- Comparative analysis of sequence data to determine superfamily origins and divergence patterns.
- Phylogenetic analysis to infer evolutionary relationships and timing of gene duplications.
Main Results:
- The short-chain form (SDR) is the most abundant, divergent, and prokaryotic-emphasized superfamily, suggesting an early origin coinciding with prokaryotic life.
- The medium-chain form (MDR) also exhibits ancient origins, with its emergence potentially occurring earlier than previously thought, possibly linked to the rise of oxidative conditions.
- Classical liver MDR-ADH traces back to a gene duplication around 550 million years ago, aligning with the early vertebrate radiation and the Cambrian explosion.
Conclusions:
- ADH evolution is characterized by distinct superfamily origins and repeated enzymogenesis, leading to current divergence.
- Evolutionary patterns of ADHs correlate with significant global events, including the emergence of cellular life and the Cambrian explosion.
- Simple molecular observations on ADH patterns provide insights into common divergence rules largely unaffected by horizontal gene transfer after initial origins.
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