Discovery of the Showdomycin Gene Cluster from Streptomyces showdoensis ATCC 15227 Yields Insight into the Biosynthetic Logic of C-Nucleoside Antibiotics.

Nucleoside antibiotics are a large class of pharmaceutically relevant chemical entities, which exhibit a broad spectrum of biological activities. Most nucleosides belong to the canonical N-nucleoside family, where the heterocyclic unit is connected to the carbohydrate through a carbon-nitrogen bond. However, atypical C-nucleosides were isolated from Streptomyces bacteria over 50 years ago, but the molecular basis for formation of these metabolites has been unknown.

Creative Math of RNA Polymerase III Termination: Sense Plus Antisense Makes More Sense.

In this issue of Molecular Cell, Arimbasseri and Maraia (2015) demonstrate that yeast RNA polymerase III integrates inputs from both strands of the DNA template and three dedicated protein subunits to trigger the highly controlled release of the nascent RNA transcript.