Electron micrograph and genetic map of Methanococcus jannaschii

Archaea look like bacteria, but biochemically and genetically, they are quite different. For example, archaea can thrive in extreme conditions that would kill other life forms. In the late 1970s, these unusual organisms were first recognized as distinct from eukaryotes (plants, animals, and other organisms whose cells have a nucleus) and prokaryotes (or bacteria, whose cells contain no distinct nucleus). This finding was verified in 1996, when a study funded by the Office of Science's Microbial Genome Initiative mapped the entire genome sequence of Methanococcus jannaschii and thereby confirmed its place in the "third branch of life," separate from prokaryotes and eukaryotes and ancestral to both. About two-thirds of the genes of M. jannaschii, a microbe from boiling vents deep in the Pacific Ocean, looked like nothing seen before in biology. The genes involved in energy production, cell division, and metabolism were similar to those in bacteria, whereas those involved in DNA transcription, translation, and replication were similar to those found in eukaryotes.

Scientific Impact: This work confirmed that archaea are separate and distinct life forms and provided the information needed to compare the three domains of life at the genomic level. M. jannaschii is also worthy of study in itself; it produces methane as a by-product of metabolism, thus offering the possibility of generating large supplies of a safe and renewable source of energy.

Social Impact: This microbe makes hundreds of enzymes that are stable at high temperatures and therefore could have practical uses in medicine, food science, and other industries. This type of research helps DOE understand the effects and by-products of energy production and identify organisms useful in environmental cleanup.

Reference: Bult, C.J., White, O., Olsen, G.J., Zhou, L., Fleischmann, R.D., Sutton, G.G., Blake, J.A., FitzGerald, L.M., Clayton, R.A., Gocayne, J.D., Kerlavage, A.R., Dougherty, B.A.,Tomb, J.F., Adams MD, Reich CI, Overbeek R, Kirkness EF, Weinstock KG, Merrick JM, Glodek, A., Scott, J.L., Geoghagen, N.S., Venter, J.C., "Complete genome sequence of the methanogenic archaeon, Methanococcus jannaschii," Science 273:1058-73 (1996).

URL: http://www.tigr.org/tigr-scripts/CMR2/GenomePage3.spl?database=arg

Technical Contact: Dr. Dan Drell, Life Sciences Division, Office of Biological and Environmental Research, 301-903-4742

Press Contact: Jeff Sherwood, DOE Office of Public Affairs, 202-586-5806

SC-Funding Office: Office of Biological and Environmental Research