Methanosarcinaceae

In taxonomy, the Methanosarcinaceae are a family of the Methanosarcinales.

Phase-contrast photo of Methanosarcina barkeri, type strain MS^T

Methanosarcinaceae
Scientific classification
Domain:	Archaea
Kingdom:	Euryarchaeota
Phylum:	Euryarchaeota
Class:	Methanomicrobia
Order:	Methanosarcinales
Family:	Methanosarcinaceae Balch and Wolfe 1981
Genera
Halomethanococcus Yu & Kawamura 1988 Methanimicrococcus Methanococcoides Methanohalobium Methanohalophilus Methanolobus Methanomethylovorans Methanosalsum Methanosarcina "Ca. Methanovorans" Chadwick et al. 2022

Phylogeny

The currently accepted taxonomy is based on the List of Prokaryotic names with Standing in Nomenclature (LPSN) and National Center for Biotechnology Information (NCBI)

16S rRNA-based LTP_01_2022	53 marker proteins based GTDB 07-RS207
Methanohalobium Zhilina & Zavarzin 1988 Methanosalsum Boone and Baker 2002 Methanococcoides Sowers and Ferry 1985 Methanohalophilus Paterek and Smith 1988 Methanomethylovorans Lomans et al. 2004 Methanolobus König and Stetter 1983 Methanimicrococcus Sprenger et al. 2000 Methanosarcina Kluyver and van Niel 1936	Methanimicrococcus Methanosarcina Methanohalobium Methanosalsum Methanococcoides Methanohalophilus Methanomethylovorans Methanolobus

Biochemistry

A notable trait of Methanosarcinaceae is that they are methanogens that incorporate the unusual amino acid pyrrolysine into their enzymes. The enzyme monomethylamine methyltransferase catalyzes the reaction of monomethylamine to methane. This enzyme includes pyrrolysine. The unusual amino acid is inserted using a unique tRNA, the anticodon of which is UAG. In most organisms, and in most Methanosarcinaceae proteins, UAG is a stop codon. However in this enzyme, and anywhere else pyrrolysine is incorporated, likely through contextual markers on the mRNA, the pyrrolysine-loaded tRNA is inserted instead of the release factor. They also have a unique aminoacyl-tRNA synthetase to specifically load this tRNA with pyrrolysine. This unique adaptation is still the subject of significant study.

See also

• List of Archaea genera

Further reading

Scientific journals

• Cavalier-Smith, T (2002). "The neomuran origin of archaebacteria, the negibacterial root of the universal tree and bacterial megaclassification". Int. J. Syst. Evol. Microbiol. 52 (Pt 1): 7–76. doi:10.1099/00207713-52-1-7. PMID 11837318.
• Springer E; Sachs MS; Woese CR; Boone DR (1995). "Partial gene sequences for the A subunit of methyl-coenzyme M reductase (mcrI) as a phylogenetic tool for the family Methanosarcinaceae". Int. J. Syst. Bacteriol. 45 (3): 554–559. doi:10.1099/00207713-45-3-554. PMID 8590683.
• Cavalier-Smith, T (1986). "The kingdoms of organisms". Nature. 324 (6096): 416–417. Bibcode:1986Natur.324..416C. doi:10.1038/324416a0. PMID 2431320. S2CID 5242667.
• Sowers KR; Johnson JL; Ferry JG (1984). "Phylogenic relationships among the methylotrophic methane-producing bacteria and emendation of the family Methanosarcinaceae". Int. J. Syst. Bacteriol. 34 (4): 444–450. doi:10.1099/00207713-34-4-444.
• Balch WE; Fox GE; Magrum LJ; Woses CR; et al. (1979). "Methanogens: reevaluation of a unique biological group". Microbiol. Rev. 43 (2): 260–296. doi:10.1128/MMBR.43.2.260-296.1979. PMC 281474. PMID 390357.

Scientific books

• Boone DR; Whitman WB; Koga Y (2001). "Order III. Methanosarcinales ord. nov.". In DR Boone; RW Castenholz (eds.). Bergey's Manual of Systematic Bacteriology Volume 1: The Archaea and the deeply branching and phototrophic Bacteria (2nd ed.). New York: Springer Verlag. pp. 169. ISBN 978-0-387-98771-2.
• Grant WD; Kamekura M; McGenity TJ; Ventosa A (2001). "Class III. Halobacteria class. nov.". In DR Boone; RW Castenholz (eds.). Bergey's Manual of Systematic Bacteriology Volume 1: The Archaea and the deeply branching and phototrophic Bacteria (2nd ed.). New York: Springer Verlag. pp. 169. ISBN 978-0-387-98771-2.