The Rickettsia rpsL leader is a putative attenuator element identified by bioinformatics within bacteria of the α-proteobacterial Rickettsia

Rickettsia

Rickettsia is a genus of non-motile, Gram-negative, non-sporeforming, highly pleomorphic bacteria that can present as cocci , rods or thread-like . Being obligate intracellular parasites, the Rickettsia survival depends on entry, growth, and replication within the cytoplasm of eukaryotic host cells...

genus. It is located upstream of the operon encoding ribosomal protein

Ribosomal protein

A ribosomal protein is any of the proteins that, in conjunction with rRNA, make up the ribosomal subunits involved in the cellular process of translation. A large part of the knowledge about these organic molecules has come from the study of E. coli ribosomes. Most ribosomic proteins have been...

s S12 and S7 (rpsL and rpsG genes respectively), and presents a Rho-independent terminator

Intrinsic termination

Intrinsic termination is a mechanism in prokaryotes that causes mRNA transcription to be stopped. In this mechanism, the mRNA contains a sequence that can base pair with itself to form a stem-loop structure 7-20 base pairs in length that is also rich in cytosine-guanine base pairs...

 at the 3' end. This RNA is presumed to operate as a non-coding ribosomal protein leader potentially interacting with the S12 or S7 proteins, encoded by the operon. The motif might be related to other rpsL leaders, such as that from Pseudomonas

Pseudomonas rpsL leader

The Pseudomonas rpsL leader is a putative attenuator RNA element identified by bioinformatics searches within bacteria of the Pseudomonadaceae phylum. It is located upstream of the operon encoding ribosomal proteins S12 and S7 , and presents a Rho-independent terminator at the 3' end...

.