Cover image

Bacterial small RNAs (sRNAs) regulate gene expression by base-pairing with their target mRNAs. Using RIL-seq data, Fisher and Margalit determine prime positions in sRNA binding sites within coding sequences (framed in black in the figure), and show that these positions are adjusted with the reading frame and often coincide with the most frequent codons. This suggests that frequent codons may facilitate sRNA–mRNA encounters and that codon usage bias influences binding site formation via selective pressures. (Image created by Shira Fisher.)