The RNA world hypothesis posits that RNA self-replication played a foundational role at the origin of life. To explore this hypothesis, researchers have used selection methods to discover RNA catalysts (ribozymes) with polymerase activity. Some such polymerase ribozymes can replicate parts of their own sequence but little about their three-dimensional structures was known. Here, we describe the determination of the structure of one such polymerase ribozyme using cryo-EM and map its functional…

In this work, synthetic cells equipped with an artificial signaling pathway that connects an extracellular trigger event to the activation of intracellular transcription are engineered. Learning from nature, this is done via an engineering of responsive enzymes, such that activation of enzymatic activity can be triggered by an external biochemical stimulus. Reversibly deactivated creatine kinase to achieve triggered production of adenosine triphosphate, and a reversibly deactivated nucleic acid…