Pyrococcus abyssi

A Microbial Biorealm page on the genus Pyrococcus abyssi

Classification

Higher order taxa

Archaea; Euryarchaeota; Thermococci; Thermococcales; Thermococcaceae; Pyrococcus

Species

NCBI: Taxonomy

Pyrococcus abyssi; 272844

Description and significance

Pyrococcus abyssi is found near deep sea hyperthermal vents off of the Southwest region of the Pacific Ocean where the temperatures can reach as high as 102C and pressures can be up to 200 atm. This organism was collected in the smoker material and sea water surrounding these hyperthermal vents. Because of their ability to survive in these extreme conditions, the genome of P. abyssi has been completely sequenced. Since not much has been studied on hyperthermophiles, P. abyssi has been used as a model organism in the laboratories. Hopefully through the analysis of this organism, better understanding and greater genetic tools can be achieved through it's study.

Genome structure

The genome of P. abyssi is circular and contains 1.76Mb. The genome content has not been explored as of yet. Most of the functionality that is known of the P. abyssi genome has come from the comparison to similiar genomes with known functions through BLAST. The comparison of the genome's of P. abyssi and P. horikoshii revealed that archaea's terminus of replication is a major region for replication, similar to that of bacteria. Comparison to another species of pyrococcus, P. furiosus, reveals an "identification of DNA reorganization linked to IS-like elements and DNA integration within tRNA genes" (1). Besides similiarities to these 2 other pyrococcus species, P. abyssi also contains genes which are crenarchaeal and bacterial like. However, these genes are mainly for the use of transport. Has a plasmid pGT5 The genome encodes for the following amino acids: Trp, Lys, Ser, Gly, Cys, Glu, Gln, Ala, Asp, and Asn. The remainder of the amino acids are not synthesized by P. abyssi.

Cell structure and metabolism

P. abyssi utilizes ATP as an energy source but has a reductant, ferrodoxin, that is different than our own. Nonetheless, ferrodoxin functions in a similar manner when it is reoxidized, leading to the creation of a electrochemical gradient which is needed for ATP synthesis. An ATPase is needed for pumping ions across the membrane. It is not known whether hydrogen or sodium ions are pumped across the membrane to create the membrane potential.

References

[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.

Cohen GN, Barbe V, Flament D, Galperin M, Heilig R, Lecompte O, Poch O, Prieur D, Querellou J, Ripp R, Thierry JC, Van der Oost J, Weissenbach J, Zivanovic Y, Forterre P. "An integrated analysis of the genome of the hyperthermophilic archaeon Pyrococcus abyssi". Molecular Microbiology. 2003 Mar;47(6):1495-512.

http://aem.asm.org/cgi/reprint/61/3/1138 Minimal Amino Acid Requirements of the Hyperthermophilic Archaeon Pyrococcus abyssi, Isolated from Deep-Sea Hydrothermal Vents Appl. Environ. Microbiol., Mar 1995, 1138-1140, Vol 61, No. 3 Copyright © 1995, American Society for Microbiology

• Georges N. Cohen, Valérie Barbe, Didier Flament, Michael Galperin, Roland Heilig, Odile Lecompte, Olivier Poch, Daniel Prieur, Joël Quérellou, Raymond Ripp, Jean-Claude Thierry, John Van der Oost, Jean Weissenbach, Yvan Zivanovic, Patrick Forterre (2003)

An integrated analysis of the genome of the hyperthermophilic archaeon Pyrococcus abyssi Molecular Microbiology 47 (6), 1495–1512. doi:10.1046/j.1365-2958.2003.03381.x

• C. Geslin,* M. Le Romancer, G. Erauso, M. Gaillard, G. Perrot, and D. Prieur. 2003. PAV1, the First Virus-Like Particle Isolated from a Hyperthermophilic Euryarchaeote, “Pyrococcus abyssi”.J Bacteriol. 2003 July; 185(13): 3888–3894.

Edited by Stephine Chow