Methanocaldococcus jannaschii
Encyclopedia
Methanocaldococcus jannaschii (formerly Methanococcus jannaschii) is a thermophilic
methanogen
ic archaea
. 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.
led by Craig Ventner using whole genome shotgun sequencing. According to Ventner, the unique features of the genome provided strong evidence that there are three domains of life
.
. 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 .
Thermophile
A thermophile is an organism — a type of extremophile — that thrives at relatively high temperatures, between 45 and 122 °C . Many thermophiles are archaea...
methanogen
Methanogen
Methanogens are microorganisms that produce methane as a metabolic byproduct in anoxic conditions. They are classified as archaea, a group quite distinct from bacteria...
ic archaea
Archaea
The Archaea are a group of single-celled microorganisms. A single individual or species from this domain is called an archaeon...
. 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.
History
Methanocaldococcus jannaschii was isolated from a hot spring at Woods holeWoods Hole Oceanographic Institution
The Woods Hole Oceanographic Institution is a private, nonprofit research and higher education facility dedicated to the study of all aspects of marine science and engineering and to the education of marine researchers. Established in 1930, it is the largest independent oceanographic research...
Sequencing
Methanocaldococcus jannaschii was sequenced by a group at TIGRJCVI
JCVI can refer to:* J. Craig Venter Institute, a multidisciplinary genomic-focused organization in the United States.* Joint Committee on Vaccination and Immunisation, an independent expert advisory committee of the United Kingdom Department of Health....
led by Craig Ventner using whole genome shotgun sequencing. According to Ventner, the unique features of the genome provided strong evidence that there are three domains of life
Domain (biology)
In biological taxonomy, a domain is the highest taxonomic rank of organisms, higher than a kingdom. According to the three-domain system of Carl Woese, introduced in 1990, the Tree of Life consists of three domains: Archaea, Bacteria and Eukarya...
.
Biology and Biochemistry
M. jannaschii is a thermophilic methanogenMethanogen
Methanogens are microorganisms that produce methane as a metabolic byproduct in anoxic conditions. They are classified as archaea, a group quite distinct from bacteria...
. It is only capable of growth on carbon dioxide
Carbon dioxide
Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...
and hydrogen
Hydrogen
Hydrogen is the chemical element with atomic number 1. It is represented by the symbol H. With an average atomic weight of , hydrogen is the lightest and most abundant chemical element, constituting roughly 75% of the Universe's chemical elemental mass. Stars in the main sequence are mainly...
as primary energy sources, unlike many other methanococci (such as Methanococcus maripalidus) which can also use formate
Formate
Formate or methanoate is the ion CHOO− or HCOO− . It is the simplest carboxylate anion. It is produced in large amounts in the hepatic mitochondria of embryonic cells and in cancer cells by the folate cycle Formate or methanoate is the ion CHOO− or HCOO− (formic acid minus one hydrogen ion). It...
as a primary energy source . The genome includes many hydrogenases, such as a 5,10-methenyltetrahydromethanopterin hydrogenase
5,10-methenyltetrahydromethanopterin hydrogenase
The 5,10-methenyltetrahydromethanopterin hydrogenase , the so-called iron-sulfur cluster-free hydrogenase, is an enzyme found in methanogenic archea such as Methanothermacter marburgensis. It was discovered and first characterized by the Thauer group at the Max Planck Institute in Marburg...
, a ferredoxin hydrogenase
Ferredoxin hydrogenase
In enzymology, a ferredoxin hydrogenase is an enzyme that catalyzes the chemical reactionThus, the two substrates of this enzyme are H2 and oxidized ferredoxin, whereas its two products are reduced ferredoxin and H+....
(eha), and a Coenzyme F420 hydrogenase
Coenzyme F420 hydrogenase
In enzymology, a coenzyme F420 hydrogenase is an enzyme that catalyzes the chemical reactionThus, the two substrates of this enzyme are H2 and coenzyme F420, whereas its product is reduced coenzyme F420....
.
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
DNA polymerase
A DNA polymerase is an enzyme that helps catalyze in the polymerization of deoxyribonucleotides into a DNA strand. DNA polymerases are best known for their feedback role in DNA replication, in which the polymerase "reads" an intact DNA strand as a template and uses it to synthesize the new strand....
family .