HopC RNA motif

The "hopC" RNA motif is a predicted cis-regulatory element identified by a bioinformatic screen for conserved RNA secondary structures. "hopC" RNAs are exclusively found within bacteria classified within the genus "Helicobacter", some of which are human pathogens that infect the stomach and can cause ulcers.
"hopC" RNAs are found upstream of an operon of two genes called "hopC" and "hopB" (also called "alpa" and "alpB"). Experiments on the start of transcription for the "hopCB" operon indicate that "hopC" RNAs lie within the 5' untranslated region of this operon. The "hopCB" operon is induced to higher levels of expression in response to low pH. This fits in with data that HopCB is involved in binding to human epithelial cells, which is presumably something that the bacteria do during infection of the low-pH environment of the stomach.
Previous work suggested that a repeat of 13 thymidine nucleotides might be involved in regulating the abundance of the "hopCB" operon. However, this 13-nucleotide region lies upstream of the transcription start site, and is therefore independent of "hopC" motif RNAs.