All living things have a fleet of tiny copy machines that turn instructions from DNA into RNA, the molecules responsible for helping build proteins that keep organisms alive. One of those nanoscale machines, called eukaryotic RNA polymerase II, performs a crucial early step required by nearly every biological process. It makes messages, copying and carrying instructions from the cell nucleus to make proteins.
Until recently, scientists had only witnessed the eukaryotic RNA at work in carefully assembled test tubes, stripped of the chaotic realities of life inside a cell. Now, a team led by Penn State researchers has captured a glimpse of this molecular machinery as it operates inside living organisms. They reported their findings in the journal Nature Communications.
"This is the first time we're seeing this process as it actually happens; the way it acts when no one is watching," said Katsuhiko Murakami, the Stanley Person Professor of Molecular Biology and director of the Huck Center for Structural Biology at Penn State and co-corresponding author on the study. "Previously, we had to use highly purified samples under ideal lab conditions to visualize their structures, which is not how life really works. Now, we must completely change our thinking because what we're seeing is not anything we have seen before."
