The ribosomal L19 leader is a putative RNA regulatory element that was found upstream of the rplS gene encoding the ribosomal protein L19 in Bacillus subtilis and other Firmicutes. The expression of another ribosomal operon in B. subtilis, infC-rpmI-rplT, is autoregulated by a complex transcription attenuation mechanism involving the formation of alternative structures in the leader mRNA which depends upon the presence of ribosomal protein L20 [17289755]. Similar transcription attenuation mechanism that can be proposed for the L19 leader has not been yet experimentally validated.