Study of Genome Sequence of World's Smallest Organism Published in PNAS; Findings Provide Evolutionary Insight Into Origin of Life
Monday October 13, 9:02 am ET
SAN DIEGO, Oct. 13 /PRNewswire/ -- Researchers at Diversa Corporation, in conjunction with Yale University and Celera Genomics, have published in the Proceedings of the National Academy of Sciences an analysis of the genome sequence and annotation of the smallest archaeal genome discovered to date, Nanoarchaeum equitans. The analysis of this genome sequence provides insight into the simplest known metabolism required by an organism for survival and supports theories that life originated in a hot and fiery primeval earth. Evolved in the most extreme of Nature's environments, the compact genome of the Nanoarchaeon parasite, N. equitans, embodies the ancient ancestry of archaeal organisms found in modern times. The unusual observation of its spatially split genes indicates the exciting probability that its proteins exemplify the actual primordial ancestors of evolutionarily modern enzymes. The genome of this Nanoarchaeon may hold the key to the deepest principles of enzyme catalysis.
WHAT: N. equitans' genome, at less than 500 kilobases, represents the
smallest genome sequenced to date. The organism, a hyperthermophilic
archaeon and the only known archaeal parasite, was discovered in a
submarine hydrothermal vent in the Kolbeinsey ridge, north of Iceland.
The genome sequence of N. equitans, completed in May 2002, was the focus
of a recent study to help determine whether it is the product of
reductive evolution driven by symbiosis and gene loss, or if the organism
is a "primitive" archaeal ancestor.
KEY FINDINGS:
-- Ribosomal protein and rRNA-based phylogenies place the branching point
of N. equitans early in the archaeal lineage, suggesting that this
microbe is a derived, but genomically stable, parasite that diverged
anciently from the archaeal lineage.
-- N. equitans lacks the genes for central metabolism, primary
biosynthesis, and bioenergetic apparatus, indicating that it is the
simplest known organism capable of survival.
-- The presence of enzymes (reverse gyrase) found only in N. equitans and
other organisms capable of living in extremely hot environments, known
as hyperthermophiles, indicates that the evolution of these organisms
was an early event and supports the hypothesis of a hot primeval
earth.
-- Engineering organisms such as N. equitans may facilitate the
development of products that can be used in biotransformations, as
biosensors, for pharmaceutical synthesis, and for biodefense. Diversa
has retained the rights to commercial applications of the organism and
to make use of the genome sequence using its proprietary genomic
technologies.
WHEN: The paper, titled "The genome of Nanoarchaeum equitans: Insights
into early archaeal evolution and derived parasitism" will be published
in an upcoming issue of the Proceedings of the National Academy of
Sciences and is available at www.pnas.org the week of October 13, 2003.
WHO: Authors are available for comment. Please contact Jason Spark at
Atkins + Associates, (858) 527-3491 or jspark@irpr.com, for additional
information. |
