The IMES-1 RNA motif is a conserved RNA

RNA

Ribonucleic acid , or RNA, is one of the three major macromolecules that are essential for all known forms of life....

 structure that was identified in marine environmental sequences by two studies based on metagenomics

Metagenomics

Metagenomics is the study of metagenomes, genetic material recovered directly from environmental samples. The broad field may also be referred to as environmental genomics, ecogenomics or community genomics. Traditional microbiology and microbial genome sequencing rely upon cultivated clonal cultures...

 and bioinformatics

Bioinformatics

Bioinformatics is the application of computer science and information technology to the field of biology and medicine. Bioinformatics deals with algorithms, databases and information systems, web technologies, artificial intelligence and soft computing, information and computation theory, software...

, the first analyzing metatranscriptome (RNA) data and the second using metagenome (DNA

DNA

Deoxyribonucleic acid is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms . The DNA segments that carry this genetic information are called genes, but other DNA sequences have structural purposes, or are involved in...

) data. These RNAs are present in environmental sequences

RNAs present in environmental samples

A wide variety of non-coding RNAs have been identified in various species of organisms known to science. However, RNAs have also been identified in "metagenomics" sequences derived from samples of DNA or RNA extracted from the environment, which contain unknown species. Initial work in this area...

, and as of 2009 are not known to be present in any cultivated species

Species

In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

. However, the species that use these RNAs are most closely related to known alphaproteobacteria

Alphaproteobacteria

Alphaproteobacteria is a class of Proteobacteria. Like all Proteobacteria, they are Gram-negative.-Characteristics:The Alphaproteobacteria comprise most phototrophic genera, but also several genera metabolising C1-compounds , symbionts of plants and animals, and a group of pathogens, the...

 and gammaproteobacteria

Gammaproteobacteria

Gammaproteobacteria is a class of several medically, ecologically and scientifically important groups of bacteria, such as the Enterobacteriaceae , Vibrionaceae and Pseudomonadaceae. An exceeding number of important pathogens belongs to this class, e.g...

. IMES-1 RNAs make up a significant portion of marine RNA transcripts and are exceptionally abundant in that over five times as many IMES-1 RNAs were found as ribosome

Ribosome

A ribosome is a component of cells that assembles the twenty specific amino acid molecules to form the particular protein molecule determined by the nucleotide sequence of an RNA molecule....

s in RNAs sampled from the Pacific Ocean

Pacific Ocean

The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...

. Only two bacterial RNAs are known (6S RNA and transfer RNA

Transfer RNA

Transfer RNA is an adaptor molecule composed of RNA, typically 73 to 93 nucleotides in length, that is used in biology to bridge the three-letter genetic code in messenger RNA with the twenty-letter code of amino acids in proteins. The role of tRNA as an adaptor is best understood by...

) to be more highly transcribed than ribosomes. IMES-1 RNAs were also detected in abundance in Block Island Sound

Block Island Sound

Block Island Sound is a strait in the open Atlantic Ocean, approximately wide, separating Block Island from the coast of Rhode Island in the United States...

 in the Atlantic Ocean

Atlantic Ocean

The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...

.