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Scientific name Methanocaldococcus jannaschii Similar Methanococcus, Archaeans, Methanocaldococcus, Archaeoglobus, Pyrococcus | ||
Methanocaldococcus jannaschii (formerly Methanococcus jannaschii) is a thermophilic methanogenic archaean in the class Methanococci. 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 were worked out biochemically in this organism, as were several other archaeal-specific metabolic pathways.
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History
Methanocaldococcus jannaschii was isolated from a submarine hydrothermal vent at Woods Hole Oceanographic Institution.
Sequencing
Methanocaldococcus jannaschii was sequenced by a group at TIGR led by Craig Venter using whole-genome shotgun 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) and is therefore sometimes referred to as a "class I" methanogen (e.g. [1]).
Biology and biochemistry
Methanocaldococcus jannaschii is a thermophilic methanogen, meaning it grows by making methane as a metabolic byproduct. It is only capable of growth on carbon dioxide and hydrogen as primary energy sources, unlike many other methanococci (such as Methanococcus maripalidus) 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 family.