Integron attI1 Sites, Not Riboswitches, Associate with Antibiotic Resistance Genes

In a recent publication in Cell (Jia et al., 2013), the authors conclude from bioinformatics, genetic, and biochemical analyses that a conserved sequence element associated with antibiotic resistance genes represents a novel widespread riboswitch class for certain aminoglycosides. Below, we point out previously reported functions for this element that were not discussed by the authors, and we note other issues with the validation experiments that raise significant concerns about the conclusions of the study.