''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
Further reading
*
*
*
*
* Jeffrey M. Dick, Everett L. Shock
The Release of Energy During Protein Synthesis at Ultramafic-Hosted Submarine Hydrothermal Ecosystems In: AGU Journal of Geophysical Research: Biogeosciences, Volume 126, Issue 11, e2021JG006436.
doi:10.1029/2021JG006436. First published: 30 October 2021. See also
New Possibilities for Life in the Strange, Dark World at the Bottom of Earth’s Ocean – And Perhaps in Oceans on Other Planetson SciTechDaily. November 28, 2021. Source: Arizona State University
External links
Microbe wiki entry for ''Methano(caldo)coccus jannaschii''UCSD genome browser entry for ''Methanocaldococcus jannaschii''KEGG entry for ''Methanocaldococcus jannaschii''Type strain of ''Methanocaldococcus jannaschii'' at Bac''Dive'' - the Bacterial Diversity Metadatabase
{{Taxonbar, from=Q6823580
Euryarchaeota
Archaea described in 1983