The ''hopC'' RNA motif is a predicted cis-regulatory element identified by a bioinformatic screen for conserved

RNA Ribonucleic acid (RNA) is a polymeric molecule essential in various biological roles in coding, decoding, regulation and expression of genes. RNA and deoxyribonucleic acid ( DNA) are nucleic acids. Along with lipids, proteins, and carbohydra ...

secondary structure Protein secondary structure is the three dimensional conformational isomerism, form of ''local segments'' of proteins. The two most common Protein structure#Secondary structure, secondary structural elements are alpha helix, alpha helices and beta ...

s. ''hopC'' RNAs are exclusively found within

bacteria Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among ...

classified within the

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

'' Helicobacter'', some of which are

human Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedalism and exceptional cognitive skills due to a large and complex brain. This has enabled the development of advanced tools, culture, ...

pathogen In biology, a pathogen ( el, πάθος, "suffering", "passion" and , "producer of") in the oldest and broadest sense, is any organism or agent that can produce disease. A pathogen may also be referred to as an infectious agent, or simply a germ ...

s 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 Transcription refers to the process of converting sounds (voice, music etc.) into letters or musical notes, or producing a copy of something in another medium, including: Genetics * Transcription (biology), the copying of DNA into RNA, the fir ...

for the ''hopCB'' operon indicate that ''hopC'' RNAs lie within the

5' untranslated region The 5′ untranslated region (also known as 5′ UTR, leader sequence, transcript leader, or leader RNA) is the region of a messenger RNA (mRNA) that is directly Upstream and downstream (DNA), upstream from the initiation codon. This region is im ...

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

epithelial Epithelium or epithelial tissue is one of the four basic types of animal tissue, along with connective tissue, muscle tissue and nervous tissue. It is a thin, continuous, protective layer of compactly packed cells with a little intercellula ...

cells, which is presumably something that the

do during infection of the low-pH environment of the stomach. Previous work suggested that a repeat of 13 thymidine

nucleotide Nucleotides are organic molecules consisting of a nucleoside and a phosphate. They serve as monomeric units of the nucleic acid polymers – deoxyribonucleic acid (DNA) and ribonucleic acid (RNA), both of which are essential biomolecules wi ...

s 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.

References

External links

* Cis-regulatory RNA elements {{molecular-cell-biology-stub