Wednesday, 1 August 2018

Iron and sulfur: the ingredients of the first ‘breath’ of life on Earth

A research team led by CIBIO of UniTrento identified the biochemical mechanism that enables cell metabolism, the process that makes the development of any life form possible

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A new research study coordinated by Sheref Mansy of CIBIO, the Centre for Integrative Biology of the University of Trento, identified for the first time the biochemical mechanism that enables cell metabolism, the process that makes the development of any life form possible.

According to the study, which was published in Nature Catalysis, iron and sulfur on the young Earth about 4 billion years ago were the main starters of the chemical processes that led to the birth of life on our planet.

The research takes off from the results achieved last year by Sheref Mansy’s team, which had discovered the importance of iron-sulfur clusters in prebiotic evolution, activated by ultraviolet light irradiation emitted by the Sun.

As the article in Nature Catalysis explains, the new study moves one step forward by recognizing the key role that these elements played in the formation of the first cellular forms that then led to more complex life forms.

All living organisms use the energy produced by digestion to fuel the vital processes that support life. This phenomenon is known as metabolism and its functioning is based on a series of chemical transformations that occur within cells. The work of Mansy’s team, with Claudia Bonfio of the University of Trento as leading author, demonstrates that iron-sulfur clusters were the first to lead to the creation of so-called pH gradients, i.e. the chemical mechanisms that allow communication across cell membranes.

This is a fundamental process through which cells collect energy, and the metabolic activity that keeps living organisms alive relies on it. Therefore iron and sulfur, basic “building blocks” on the very young Earth, made life possible on our planet.

This result not only explains the origin of the first organic molecules on Earth, but may also help find other life forms in the Universe. Only a few days ago, for instance, the presence of liquid water on Mars was confirmed by an Italian research team: it is not unlikely that these iron-sulfur clusters played a part in the development of primitive living organisms on the red planet.

The study, recently published in Nature Catalysis, was funded by the Simons Foundation and the Armenise-Harvard Foundation.

Sheref Mansy, , research leader, moved to Trento in 2009 after receiving the Career Development Award from the Armenise-Harvard Foundation, and opened the Origins of Life and Synthetic Biology Lab at CIBIO. The purpose of the laboratory is to find a middle ground between living and non-living systems at cellular level: in particular, to build cells that can “breathe” artificially. This work may help identify with increasing precision the biochemical mechanisms that made the first signs of life possible on Earth.