Scientists have succeeded in achieving a major biological breakthrough that will greatly help advance the understanding of the evolution of microorganisms like bacterial enzymes. Researchers at Leipzig University were able to reconstruct 2-billion-year-old enzymes and believe the achievement could prove to be the missing puzzle in the evolution of bacterial enzymes.
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The reconstruction of a specific RNA polymerase, an enzyme that catalyzes the production of new DNA and RNA from an existing strand of DNA or RNA, as it existed approximately 2 billion years ago, allowed the researchers to now understand the features of equivalent modern enzymes.
The study, published in the journal Molecular Biology and Evolution, was centered on understanding more about tRNA nucleotidyltransferases: enzymes that attach three nucleotide building blocks in the sequence C-C-A to small RNAs in the cell (so-called transfer RNAs) so that they can subsequently supply amino acids for protein synthesis.
For years, scientists have tried to find out why bacterial and eukaryotic enzymes exhibited an unexpected and surprisingly low tRNA substrate affinity while they efficiently catalyze the CCA addition.
To get around the problem, they utilized ancestral sequence reconstruction (ASR) to study a reconstructed candidate of a 2-billion-year-old enzyme, CCA-adding enzyme from Gammaproteobacteria, to the matching current enzyme from Escherichia coli. Lead researchers Mario Mörl (Biochemistry) and Sonja Prohaska (Bioinformatics) found that while both enzymes worked with similar precision, they displayed clear differences in terms of reaction, Phys.org reported.
“Until now, it was not possible to recognize the tendency of modern enzymes to repeatedly interrupt their activity as an evolutionary advantage. This phenomenon had puzzled biochemists for decades. It was only in comparison with the mode of activity of the reconstructed enzyme, that the mystery has now been solved,” the report added.
“We have now finally been able to explain why modern tRNA nucleotidyltransferases work so efficiently despite their distributive nature,” Mario Mörl was quoted as saying by Phys.org. “The finding took us in the team completely by surprise. We didn’t expect anything like this.”
According to Mörl, the study was able to answer a question that was initially raised 20 years ago, adding that it had only been made possible through bioinformatics reconstruction methods.
Scientists can now say for sure that the distributive manner in which modern enzymes work is an evolutionary progress. They believe that by using ancestral sequence reconstruction (ASR) to explore other behaviors that have perplexed scientists for years, they can learn a lot more about the evolution and features of present enzymes.
Finding encouragement from the findings, Mörl believes a continued engagement between bioinformatics and biochemistry should become a norm. Moreover, coordination between computer calculations and laboratory experiments could solve many more scientific mysteries.
“This close cooperation between bioinformatics and biochemistry has existed in Leipzig for several years and has proven, not for the first time, to be a great advantage for both sides,” he added.