ChiX is a small RNA that coordinately regulates the gene expression of chitin-degrading enzymes and the uptake system of chitin degradation products in Serratia marcescens. Although ChiX suppressed the expression of chitin-degrading enzyme genes by suppressing its translation by base pairing with chiR mRNA encoding transcriptional factor, the expression of chiP led to the derepression of chiR by ChiX. The chiP mRNA was capable of base pairing with the region extending before and after the terminator of ChiX, which suggested that ChiX switched the target from chiR mRNA to chiP mRNA.