Central dogma alchemy

Reflecting on the results of studies of RNA from the last 20 years, one might gain the impression that RNA could be a protein in clever disguise. For decades, RNA had primarily occupied a place in the central dogma of molecular biology as a transient messenger that passively conveys cellular genetic information in a directional flow that starts with DNA, proceeds through RNA, and finally culminates in protein synthesis. Aside from that fleeting role, RNA was also perceived to make more permanent but passive structural contributions as a scaffold for the ribosome or to present anticodons in tRNA. Although these functions for RNA are certainly not entirely inaccurate, the past two decades have revealed that the nucleic acid plays numerous, information-rich, and versatile roles rivaling those often assigned to proteins. The picture emerging from the key advances in the last two decades is that RNA is a chemist, modulator of …