Shocking new research from Harold A. Cruz and his research team have revealed some startling discoveries about ribose. This five-carbon sugar molecule is key to creating RNA and DNA. The research published in Angewandte Chemie International Edition underscores the peculiar properties of ribose. These properties would likely have been absolutely essential to the emergence of complex molecules on primordial Earth.
Of the many sugars ribose shows an extraordinary reactivity. It is more reactive and it favors the formation of five-member ring structures, or ribofuranose. Of course, this unique form is important, for it is the structure found in contemporary RNA and DNA. The publication uncovers how, in chemical reactions, ribose uniquely produces only ring-like structures with five corners. This unusual feature might just be one of the most important reasons for life’s earliest existence.
Krishnamurthy’s recent work has provided insight into how ribose could have reacted with diamidophosphate, which is capable of catalyzing phosphorylations. The results further indicate that a significant percentage of the ribose molecules undergo a rearrangement into a form that’s capable of reacting with a nuclear base. This process produces nucleotides — the key building blocks of RNA and DNA. This selective phosphorylation demonstrates that ribose is special among the four sugars considered in its reactivity. This underscores ribose’s ideal prebiotic chemistry bonafides.
“What we got was a 2-in-1: We showed that ribose is selectively phosphorylated from a mixture of sugars, and we also showed that this selective process produces a molecule with a form that is conducive for making RNA,” – Krishnamurthy.
The impact of this research goes beyond informing our understanding of how complex biomolecules first formed on Early Earth. In doing so, Krishnamurthy raises other important questions about how ribose would behave in protocells. He proposes that if ribose can be focused and energetically engaged in nucleotide formation, it might initiate essential reactions needed for cellular duplication and proliferation.
“If we can make that happen, it might produce enough tension to force the protocell to grow and divide — which is exactly what underpins how we grow,” – Krishnamurthy.
So what’s special about ribose? Its capacity to polymerize nucleotides is key in our pursuit to uncover the origins of life’s mysteries. The study provides remarkable evidence. Krishnamurthy cautions that it’s premature to draw firm conclusions about the evolutionary path taken by RNA and DNA based on this work alone.
“Studying these types of chemistries helps us understand what sort of processes might have led to the molecules that constitute life today, but we are not making the claim that this selection is what led to RNA and DNA, because that’s quite a leap,” – Krishnamurthy.
