Thaindian News

Washington, Feb 23 (ANI): Scientists have created an extremely small RNA molecule that can catalyze a key reaction needed to synthesize proteins, the building blocks of life, which could be a substantial step toward understanding “the very origin of Earthly life.”

The molecule was developed by University of Colorado at Boulder graduate student Rebecca Turk, research associate Nataliya Chumachenko and Professor Michael Yarus of the molecular, cellular and developmental biology department.

Cellular RNA can have hundreds or thousands of its basic structural units, called nucleotides.

Yarus’ team focused on a ribozyme - a form of RNA that can catalyze chemical reactions - with only five nucleotides.

Because proteins are complex, one vexing question is where the first proteins came from, according to Tom Blumenthal, a professor and chair of the MCDB department.

“It now appears that the first catalytic macromolecules could have been RNA molecules, since they are somewhat simpler, were likely to exist early in the formation of the first life forms, and are capable of catalyzing chemical reactions without proteins being present,” he said.

“In this paper, the Yarus group has made the amazing discovery that even an extremely tiny RNA can by itself catalyze a key reaction that would be needed to synthesize proteins,” Blumenthal said.

“Nobody expected an RNA molecule this small and simple to be able to do such a complicated thing as that,” he said.

The finding adds weight to the “RNA World” hypothesis, which proposes that life on Earth evolved from early forms of RNA.

“This work shows that RNA enzymes could have been far smaller, and therefore far easier to make under primitive conditions, than anyone has expected,” said Yarus.

If very simple RNA molecules such as the product of the Yarus lab could have accelerated chemical reactions in Earth’s primordial stew, the chances are much greater that RNA could direct and accelerate biochemical reactions under primitive conditions.

“Before the advent of RNA, most biologists believe, there was a simpler world of chemical replicators that could only make more of themselves, given the raw materials of the time,” Yarus said.

“If there exists that kind of mini-catalyst, a ’sister’ to the one we describe, the world of the replicators would also jump a long step closer and we could really feel we were closing in on the first things on Earth that could undergo Darwinian evolution,” he said.

“In other words, we may have taken a substantial step toward the very origin of Earthly life,” he added. (ANI)