Smallest RNA molecule engineered in CU's labs

The processes that led to life on Earth are an unsolved puzzle. But the labs here at CU’s MCDB department are starting to find the pieces — and they’re really small.

“We took something big and chopped it into pieces. And it turned out that you can make tiny pieces, and they would still be active. That was the surprise. So we actually engineered a tiny thing, an unexpectedly tiny thing,” said Mike Yarus, professor in the molecular, cellular and developmental department.

Nobody thought that the tiny thing, called a ribozyme, could have carried out the chemical reactions needed to synthesize proteins, the building blocks of life.

Ribozymes are a form of RNA, or ribonucleic acid, ordinarily composed of hundreds or thousands of structural units called nucleotides.

“Prior to this work, most of the RNA enzymes that were found or synthesized were usually a couple hundred nucleotides, or units long,” said Rebecca Turk, Ph. D. candidate in MCDB.

“This one is only five nucleotides long. So it’s much, much smaller than any of the other RNA enzymes that have been found either from life or that have been synthesized in the lab,” said Turk.

It took nearly four years for Yarus, Turk and another grad student to create the tiny ribozyme.

“We’d like to know if other tiny things exist, if you can do other reactions with these miniscule RNAs that we’ve started to study, and we need to know how this one works,” said Yarus. “But there’s a lot yet to be done.”

“We’re studying something that’s also relevant to biomedical questions of how cells work, even here in Boulder,” said Yarus.

The work of Yarus and his students was recently described in a paper published in the proceedings of the National Academy of Science.