Evolutionary time travel reveals enzymes origins, possible future designs

Researchers have used evolutionary "time travel" to learn how an enzyme evolved over time, from one of Earth's most ancient organisms to modern-day humans.

Magnus Wolf-Watz, who is at Ume? University in Sweden, looked back some 2 to 3 billion years to primitive organisms known as archaea.

A branch of archaea known as the Asgard phylum, discovered in 2015, comprises the closest known ancestors to eukaryotic cells. Odin archaea have an enzyme called adenylate kinase (AK), which is also found in prokaryotes and eukaryotes. Wolf-Watz previously studied two human types of this enzyme, AK1 and AK3.

The archaeal AK contains three copies of the enzyme (known as a trimer) that bind to each other through a helical structure. In human AKs, a mutation in this region makes the enzyme copies unable to stick to each other. The human enzymes, which function independently, are almost 1,000-fold more active

The trimer could have been more stable in the extreme environment of hydrothermal vents, but the human enzymes might have traded this thermostability for higher activity, which is important in a cooler environment, Wolf-Watz says.

Next, the researchers want to engineer novel enzymes that could be useful in organic synthesis or drug development. They also want to examine other enzymes from Odin archaea and study how they might have evolved over the eons.