Researchers have investigated the evolution of metal-binding proteins over billions of years.
Addressing one of the deepest unanswered questions in biology, a team led by Rutgers discovered protein structures that could be responsible for the origin of life in the primordial soup of ancient Earth.
The study appears in a journal Advances in science.
Researchers have investigated how primitive life could have originated on our planet from simple, inanimate materials. They asked what properties define life as we know it and concluded that all living things would be needed to collect and use energy, from sources like the Sun or hydrothermal sources.
In molecular terms, this would mean that the ability to mix electrons was paramount to life. Since the best elements for electron transfer are metals (we mean standard electrical wires), and most biological activities are carried out by proteins, the researchers decided to investigate the combination of these two elements, ie proteins that bind metals.
They compared all existing metal-binding protein structures to establish any common features, assuming that these common features were present in ancestral proteins and were diverse and transmitted to create the range of proteins we see today.
The evolution of protein structures involves understanding how new folds originated from pre-existing ones, so researchers devised a computational method that found that the vast majority of currently existing metal-binding proteins are somewhat similar regardless of the type of metal they bind to, the organism to which they bind . derived from or function assigned to the protein as a whole.
“We saw that the nuclei of existing metal-binding proteins are indeed similar, although the proteins themselves may not be,” said study leader Yana Bromberg, a professor in the Department of Biochemistry and Microbiology at Rutgers University in New Brunswick. “We have also seen that these metal cores are often composed of repeated substructures, such as LEGO blocks. Interestingly, these blocks were also found in other protein regions, not only in metal-binding nuclei, and in many other proteins not considered in our study. Our observation suggests that the rearrangement of these small building blocks may have had one or a small number of common ancestors and led to a whole range of proteins and their functions that are currently available – that is, life as we know it. “
“We have very little information about how life came to be on this planet, and our work contributes to a previously inaccessible explanation,” said Bromberg, whose research focuses on deciphering DNA blueprint molecular machine life. “This explanation could also potentially contribute to our search for life on other planets and planetary bodies. Our finding of specific structural building blocks is also likely relevant to synthetic biology efforts, where scientists want to reconstruct specifically active proteins. ”
Reference: “Quantification of structural relationships of metal binding sites suggests the origin of biological electron transfer” 14 January 2022, Advances in science.
Study, funded by OUR, also included researchers from the University of Buenos Aires.