''Methanocaldococcus jannaschii'' (formerly ''Methanococcus jannaschii'') is a thermophilic methanogenic

archaea Archaea ( ; singular archaeon ) is a domain of single-celled organisms. These microorganisms lack cell nuclei and are therefore prokaryotes. Archaea were initially classified as bacteria, receiving the name archaebacteria (in the Archaeba ...

n in the class

Methanococci Methanococci is a class of methanogenic archaea in the phylum Euryarchaeota.See the NCBIbr>webpage on Methanococci Data extracted from the They can be mesophilic, thermophilic A thermophile is an organism—a type of extremophile—that t ...

. It was the first archaeon to have its complete genome sequenced. The sequencing identified many genes unique to the archaea. Many of the synthesis pathways for methanogenic

cofactors Cofactor may also refer to: * Cofactor (biochemistry), a substance that needs to be present in addition to an enzyme for a certain reaction to be catalysed * A domain parameter in elliptic curve cryptography, defined as the ratio between the order ...

were worked out biochemically in this organism, as were several other archaeal-specific metabolic pathways.

History

''Methanocaldococcus jannaschii'' was isolated from a submarine hydrothermal vent at

Woods Hole Oceanographic Institution The Woods Hole Oceanographic Institution (WHOI, acronym pronounced ) is a private, nonprofit research and higher education facility dedicated to the study of marine science and engineering. Established in 1930 in Woods Hole, Massachusetts, i ...

Sequencing

''Methanocaldococcus jannaschii'' was sequenced by a group at TIGR led by

Craig Venter John Craig Venter (born October 14, 1946) is an American biotechnologist and businessman. He is known for leading one of the first draft sequences of the human genome and assembled the first team to transfect a cell with a synthetic chromosome. ...

using whole-genome

shotgun sequencing In genetics, shotgun sequencing is a method used for sequencing random DNA strands. It is named by analogy with the rapidly expanding, quasi-random shot grouping of a shotgun. The chain-termination method of DNA sequencing ("Sanger sequencing ...

. ''Methanocaldococcus jannaschii'' represented the first member of the Archaea to have its genome sequenced. According to Venter, the unique features of the genome provided strong evidence that there are three domains of life.

Taxonomy

''Methanocaldoccus jannaschii'' is a member of the genus '' Methanocaldococcus'' (previously a part of ''

Methanococcus ''Methanococcus'' is a genus of coccoid methanogens of the family Methanococcaceae. They are all mesophiles, except the thermophilic '' M. thermolithotrophicus'' and the hyperthermophilic '' M. jannaschii''. The latter was discovered at the b ...

'') and is therefore sometimes referred to as a "class I" methanogen (e.g

.

Biology and biochemistry

''Methanocaldococcus jannaschii'' is a thermophilic methanogen, meaning it grows by methanogenesis, making methane as a metabolic byproduct. It is only capable of growth on

carbon dioxide Carbon dioxide ( chemical formula ) is a chemical compound made up of molecules that each have one carbon atom covalently double bonded to two oxygen atoms. It is found in the gas state at room temperature. In the air, carbon dioxide is t ...

and

hydrogen Hydrogen is the chemical element with the symbol H and atomic number 1. Hydrogen is the lightest element. At standard conditions hydrogen is a gas of diatomic molecules having the formula . It is colorless, odorless, tasteless, non-to ...

as primary energy sources, unlike many other methanococci (such as '' Methanococcus maripaludis'') which can also use formate as a primary energy source. The genome includes many hydrogenases, such as a 5,10-methenyltetrahydromethanopterin hydrogenase, a ferredoxin hydrogenase (eha), and a coenzyme F420 hydrogenase. Proteomic studies showed that ''M. jannaschii'' contains a large number of inteins: 19 were discovered by one study. Many novel metabolic pathways have been worked out in ''M. jannaschii'', including the pathways for synthesis of many methanogenic cofactors, riboflavin, and novel amino acid synthesis pathways. Many information processing pathways have also been studied in this organism, such as an archaeal-specific

DNA polymerase A DNA polymerase is a member of a family of enzymes that catalyze the synthesis of DNA molecules from nucleoside triphosphates, the molecular precursors of DNA. These enzymes are essential for DNA replication and usually work in groups to crea ...

family. Information about

single-pass transmembrane protein A single-pass membrane protein also known as single-spanning protein or bitopic protein is a transmembrane protein that spans the lipid bilayer only once. These proteins may constitute up to 50% of all transmembrane proteins, depending on the orga ...

s from ''M. jannaschii'' was compiled in Membranome database.

References

External links