Identifying how the chemical subsystems of metabolism have changed

Feb 25, 2014

To better understand the emergence of life, former SFI Omidyar Fellow Rogier Braakman and External Professor Eric Smith are taking a careful look at Aquifex aeolicus.

Being restricted to extreme, boiling hot spring habitats (a consistent feature of Earth's geology) means the unusual bacterium's metabolic network has evolved less than those of other species. This makes it a great model system to study the early of metabolism, the researchers say.

The pair is using a technique called phylometabolic analysis, which combines the building of gene-based family trees of relatedness (called phylogenies) with reconstruction of chemical metabolic networks. This lets the researchers "see not just what information is changing, but how specific driving forces are changing the underlying chemical networks encoded by those genes," explains Braakman.

Their research, published February 5 in PLOS ONE, highlights three main drivers of evolution: optimizing kinetics, either by replacing generalist enzymes with multiple, specialized enzymes or by fusing successive enzymes in a pathway together to minimize diffusion; and optimizing thermodynamics by choosing pathways that use less energy. These drivers, they say, evoke a major tradeoff in evolution – speed versus efficiency – and suggest that early ancestors probably started with a smaller assortment of enzymes, each of which could weakly catalyze many different reactions.

By identifying how the chemical subsystems of metabolism have changed, researchers might infer phenotypic features of the universal common ancestor, notes Braakman, and even link the competition for resources across different branches of the tree of life to the evolution of the major elemental cycles in the biosphere.

Explore further: Experimental progress begins to fill gaps in hypotheses for life's emergence

More information: Braakman R, Smith E (2014) "Metabolic Evolution of a Deep-Branching Hyperthermophilic Chemoautotrophic Bacterium." PLoS ONE 9(2): e87950. DOI: 10.1371/journal.pone.0087950

add to favorites email to friend print save as pdf

Related Stories

Finding the roots and early branches of the tree of life

Apr 19, 2012

A study published in PLoS Computational Biology maps the development of life-sustaining chemistry to the history of early life. Researchers Rogier Braakman and Eric Smith of the Santa Fe Institute traced the six methods of car ...

'Promiscuous' enzymes still prevalent in metabolism

Aug 30, 2012

Open an undergraduate biochemistry textbook and you will learn that enzymes are highly efficient and specific in catalyzing chemical reactions in living organisms, and that they evolved to this state from ...

Recommended for you

Sugar mimics guide stem cells toward neural fate

19 hours ago

Embryonic stem cells can develop into a multitude of cells types. Researchers would like to understand how to channel that development into the specific types of mature cells that make up the organs and other structures of ...

Researchers uncover secrets of internal cell fine-tuning

Jul 29, 2014

New research from scientists at the University of Kent has shown for the first time how the structures inside cells are regulated – a breakthrough that could have a major impact on cancer therapy development.

User comments : 0