Giant, Ornate, Lake- and Lactobacillales-Derived (GOLLD) RNA is a 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 ...

structure present in

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 ...

. GOLLD RNAs were originally detected based on

metagenome Metagenomics is the study of genetic material recovered directly from environmental or clinical samples by a method called sequencing. The broad field may also be referred to as environmental genomics, ecogenomics, community genomics or microb ...

sequences of DNA isolated from

Lake Gatun Gatun Lake ( es, Lago Gatún) is a large freshwater artificial lake to the south of Colón, Panama. At approximately above sea level, it forms a major part of the Panama Canal, carrying ships of their transit across the Isthmus of Panama. Gatun ...

in Panama. However, they are known to be present in at least eight strains of cultivated bacteria. GOLLD RNAs are extraordinarily large compared to other RNAs with a conserved, complex

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 ...

, and average roughly 800 nucleotides. Such large, complex RNAs are often

ribozyme Ribozymes (ribonucleic acid enzymes) are RNA molecules that have the ability to catalyze specific biochemical reactions, including RNA splicing in gene expression, similar to the action of protein enzymes. The 1982 discovery of ribozymes demonst ...

s, although the biochemical function of GOLLD RNAs remains unknown. The discovery of large RNAs like GOLLD RNAs among bacteria that are mostly uncultivated under laboratory conditions suggests that many other unusually large RNAs might be found in bacteria that have not yet been studied. The GOLLD RNA in ''

Lactobacillus brevis ''Levilactobacillus brevis'' is a gram-positive, rod shaped species of lactic acid bacteria which is heterofermentative, creating CO2, lactic acid and acetic acid or ethanol during fermentation. ''L. brevis'' is the type species of the genus ''Le ...

'' ATCC 367 was studied experimentally. This GOLLD RNA is apparently encoded by a

prophage A prophage is a bacteriophage (often shortened to "phage") genome that is integrated into the circular bacterial chromosome or exists as an extrachromosomal plasmid within the bacterial cell. Integration of prophages into the bacterial host is the c ...

, and its transcription is increased during the phage

lytic cycle The lytic cycle ( ) is one of the two cycles of viral reproduction (referring to bacterial viruses or bacteriophages), the other being the lysogenic cycle. The lytic cycle results in the destruction of the infected cell and its membrane. Bacter ...

. Therefore, this GOLLD RNA presumably serves a function that is useful to the phage during this process. GOLLD RNAs are often located near

transfer RNA Transfer RNA (abbreviated tRNA and formerly referred to as sRNA, for soluble RNA) is an adaptor molecule composed of RNA, typically 76 to 90 nucleotides in length (in eukaryotes), that serves as the physical link between the mRNA and the amino ac ...

s (tRNAs), and in some cases a tRNA is predicted to be inside the GOLLD RNA structure itself. However, the biological reason underlying this association is not understood. A more recently discovered large bacterial RNA, named the ROOL RNA motif, shares properties with GOLLD RNAs. In addition to the relatively large size and high degree of structural complexity of these RNA motifs, they both are only sometimes located in prophages and often located nearby to tRNAs. However, the sequence and structures of GOLLD and ROOL RNAs are not related. The

Rfam Rfam is a database containing information about non-coding RNA (ncRNA) families and other structured RNA elements. It is an annotated, open access database originally developed at the Wellcome Trust Sanger Institute in collaboration with Janel ...

model of GOLLD RNA uses only the 3' half of GOLLD, as this region of the full RNA is highly consistent in its structure.

References

Non-coding RNA {{molecular-cell-biology-stub