Front Cover: An Unintentional Discovery of a Fluorogenic DNA Probe for Ribonuclease I (ChemBioChem 4/2020)

Serendipity : We report the discovery of RFA13‐1, a fluorogenic DNA probe, isolated from a DNA pool (left) against the bacterium Clostridium difficile , which was unintentionally contaminated by another bacterium Klebsiella aerogenes (right). The molecular target of RFA13‐1 has been identified as ribonuclease I from K. aerogenes . We found the selected DNA sequence in RFA13‐1 can assist RNase I (the sharp axe) to efficiently cleave a ribonucleotide embedded in a DNA and shielded by a pair of fluorophore‐labelled and quencher‐labelled nucleotides. More information can be found in the communication by Y. Li et al. on page 464 in Issue 4, 2020 (DOI: 10.1002/cbic.201900455).