Methanothermobacter thermautotrophicus

A Microbial Biorealm page on the genus Methanothermobacter thermautotrophicus

Classification

Higher order taxa

Cellular organisms; Archaea; Euryarchaeota; Methanobacteria;Methanobacteriales; Methanobacteriaceae; Methanothermobacter

Species

NCBI: Taxonomy

Methanothermobacter thermautotrophicus

Description and significance

Methanothermobacter thermautotrophicus is a methanogenic Gram-positive microorganism with a cell wall consisting of pseudomurein. This organism is a strictly anaerobic, nonmotile, methane producting archeon. Growth occurs at a pH of 7.2-7.6. This organism is found in thermophilic, anaerobic sewage sludge digestors. Energy metabolism is by the reduction of carbon dioxide to methane. This strain was isolated from sewage sludge in 1971 in Urbana, Illinois.

So far only two prophage pseudomurein autolysins, PeiW and PeiP, have been reported. PeiW and PeiP contain two different N-terminal pseudomurein cell wall binding domains. This finding was used to identify a novel domain, PB007923, on the M. thermautotrophicus genome present in 10 predicted open reading frames. Three homologues were identified in the Methanosphaera stadtmanae genome. Binding studies of fusion constructs of three separate PB007923 domains to green fluorescent protein revealed that it also constituted a cell wall binding domain. Both prophage domains and the PB007923 domain bound to the cell walls of Methanothermobacter species and fluorescence microscopy showed a preference for the septal region. Domain specificities were revealed by binding studies with other pseudomurein-containing archaea. Localized binding was observed for M. stadtmanae and Methanobrevibacter species, while others stained evenly. The identification of the first pseudomurein cell wall binding domains reveals the dynamics of the pseudomurein cell wall and provides marker proteins to study the extracellular pseudomurein biology of M. thermautotrophicus and of other pseudomurein-containing archaea.

http://www.ncbi.nlm.nih.gov/sutils/static/GP_IMAGE/Diversity.jpg

Genome structure

Methanothermobacter thermautotrophicus consist of 1 chromosome and is linear.

Describe the size and content of the genome. How many chromosomes? Circular or linear? Other interesting features? What is known about its sequence? Does it have any plasmids? Are they important to the organism's lifestyle?

Cell structure and metabolism

The MCM complex from the archaeon Methanother-mobacter thermautotrophicus is a model for the eukaryotic MCM2-7 helicase. Electron-microscopy single-particle reconstructions of a DNA treated M.thermautotrophicus MCM sample and a ADP.AlF(x) treated sample, respectively assembling as double hexamers and double heptamers. The electron-density maps display an unexpected asymmetry between the two rings, suggesting that large conformational changes can occur within the complex. The structure of the MCM N-terminal domain, as well as the AAA+ and the C-terminal HTH dom-ains of ZraR can be fitted into the reconstructions. Distinct configurations can be modelled for the AAA+ and the HTH domains, suggesting the nature of the conformational change within the complex. The pre-sensor 1 and the helix 2 insertions, important for the activity, can be located pointing towards the centre of the channel in the presence of DNA. We propose a mechanistic model for the helicase activity, based on a ligand-controlled rotation of the AAA+ subunits. Describe any interesting features and/or cell structures; how it gains energy; what important molecules it produces.

Ecology

Describe any interactions with other organisms (included eukaryotes), contributions to the environment, effect on environment, etc.

Pathology

How does this organism cause disease? Human, animal, plant hosts? Virulence factors, as well as patient symptoms.

Application to Biotechnology

Does this organism produce any useful compounds or enzymes? What are they and how are they used?

Current Research

Enter summaries of the most recent research here--at least three required

References

Touzel JP, Wasserfallen A, Blotevogel K, Boone DR & Mah RA, Zhilina TN & Ilarionov SA, Skerman VBD, Kotelnikova SV Global Biodiversity Information Facility PubMed

[http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=17062628&query_hl=28&itool=pubmed_docsum Nucleic Acids Res. 2006;34(20):5829-38. Epub 2006 Oct 24. Costa A, Pape T, van Heel M, Brick P, Patwardhan A, Onesti S. Structural basis of the Methanothermobacter thermautotrophicus MCM helicase activity PubMed]

[http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=17427286&query_hl=1&itool=pubmed_docsum Mol Microbiol. 2006 Dec;62(6):1618-30 Steenbakkers PJ, Geerts WJ, Ayman-Oz NA, Keltjens JT Department of Microbiology, Radboud University Nijmegen, Toernooiveld 1, 6525 ED Nijmegen, the Netherlands PubMed]

[Sample reference] Takai, K., Sugai, A., Itoh, T., and Horikoshi, K. "Palaeococcus ferrophilus gen. nov., sp. nov., a barophilic, hyperthermophilic archaeon from a deep-sea hydrothermal vent chimney". International Journal of Systematic and Evolutionary Microbiology. 2000. Volume 50. p. 489-500.

Edited by student of Anthony Kim