Lab is one step closer to understanding how life began on Earth

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How did life on Earth begin and could it be elsewhere? Researchers at Simon Fraser University have isolated a genetic gene – an enzyme called RNA polymerase – that provides new insights into the origin of life. The research is published today in the journal Science.

Researchers in the laboratory of SFU professor of molecular biology and biochemistry Peter Unrau are working to advance the Global Hypothesis of RNA in response to fundamental questions about the onset of life.

This hypothesis suggests that life on our planet began with self-reproducing ribonucleic acid (RNA) molecules, capable of not only carrying genetic information but also driving re-transmission. -cemical elements essential for life, before the growth of deoxyribonucleic acid (DNA) and proteins, which were now performing both functions within our cells.

Through an in vitro laboratory evolution process, the team has isolated a promoter-based ribozyme RNA polymerase – an enzyme capable of synthesizing RNA using RNA as a template – which has process clamping capabilities equivalent to today’s protein polymerases.

“This RNA polymerase has many of the properties of a modern protein polymerase; it was developed to recognize a promoter of RNA, and subsequently, to process RNA by copying it,” says Unrau. “What our findings mean is that a similar RNA enzyme early in life evolution may have exhibited such negligible biological characteristics.”







In early life, polymerases were made from RNA-like RNA genomes and maintained a metabolic RNA enzyme essential for life. The ribozyme RNA polymerase clamping uses a specificity primer to identify an RNA promoter. Once localized, the polymerase reshapes a process complex, capable of copying expanded sections of template. This recognition and promotional processing is similar to many aspects of transcription dependent on modern stimuli and shows how early in evolution RNA genes can be reproduced and expressed. Credit: Simon Fraser University

There is evidence to suggest that RNA preceded DNA and proteins. For example, the ribosome, the ‘machine’ that makes proteins in our cells, is derived from RNA. But better proteins have a catalyzing reaction.

This has led experts to believe that this device was a device of the late RNA world that was never eradicated by evolution.

DNA is also made from RNA. Given that RNAs are jack-of-all-trades and can perform the functions of both protein and DNA, this suggests that DNA and later proteins evolved as a regenerator. ‘to augment RNA-supported cell functions from the outset.

The polymerase clamping ribozyme discovered by Unrau’s laboratory, which is located within the Burnaby domain at SFU, indicates that RNA reproduction by RNA catalysts may indeed be possible in such a primary life.

The long-term goal of Unrau and his team is to build a self-growing system in the laboratory. This would involve the formation of a ribozyme RNA polymerase that could also reproduce and maintain, to gain a deeper understanding of how early RNA-based organisms evolved.







In early life, polymerases made from RNA would reproduce RNA genomes and maintain a metabolic RNA enzyme essential for life. RNA clamping polymerase ribozyme uses a special primer to identify an RNA promoter. Once localized, the polymerase reshapes a process complex, capable of copying expanded sections of template. This recognition and promotional processing is similar to many aspects of transcription dependent on modern stimuli and demonstrates how early in evolution RNA genes could be reproduced and expressed. Credit: Simon Fraser University

“If we could create an RNA-based living and evolutionary system in the laboratory we would have done something truly amazing, something that has never been like since the beginning of life on this planet,” says Unrau. written the science article by SFU Ph.D. student Razvan Cojocaru.

“By understanding the fundamental complexity of life, in the laboratory, we can begin to estimate the life chances on other planets and determine what it seems to have been or is. planets like Mars still have the potential to harbor life. ”


Scientists are taking a major step towards recreating a primordial ‘RNA world’ 4 billion years ago


Further information:
Razvan Cojocaru et al, Process RNA polymerization and promoter recognition in the RNA World, Science (2021). DOI: 10.1126 / science.abd9191

Presented by Simon Fraser University

Citation: Lab one step closer to understanding how life on Earth (2021, March 19) began on March 19, 2021 retrieved from https://phys.org/news/2021-03-lab-closer -life-earth.html

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