Microbiology news and views
J. Mol. Micro. Biotechnol. 4: 453-461
The Genome of Methanosarcina mazei: Evidence for Lateral Gene
Transfer Between Bacteria and Archaea
Uwe Deppenmeier, Andre Johann, Thomas Hartsch, Rainer Merkl, Ruth A.
Schmitz, Rosa Martinez-Arias, Anke Henne, Arnim Wiezer, Sebastian Bäumer, Carsten
Jacobi, Holger Brüggemann, Tanja Lienard, Andreas Christmann, Mechthild Bömeke,
Silke Steckel, Anamitra Bhattacharyya, Athanasios Lykidis, Ross Overbeek,
Hans-Peter Klenk, Robert P. Gunsalus, Hans-Joachim Fritz, Gerhard Gottschalk
The Archaeon Methanosarcina mazei and related species are of great
ecological importance as they are the only organisms fermenting acetate, methylamines
and methanol to methane, carbon dioxide and ammonia (in case of methylamines).
Since acetate is the precursor of 60% of the methane produced on earth these
organisms contribute significantly to the production of this greenhouse gas, e.g. in rice
paddies. The 4,096,345 base pairs circular chromosome of
M. mazei is more than twice as large as the genomes of the methanogenic Archaea currently completely
sequenced (Bult et al., 1996; Smith et
al., 1997). 3,371 open reading frames (ORFs) were
identified. Based on currently available sequence data 376 of these ORFs are
Methanosarcina-specific and 1,043 ORFs find their closest homologue in the bacterial domain.
544 of these ORFs reach significant similarity values only in the bacterial domain.
They include 56 of the 102 transposases, and proteins involved in
gluconeo-genesis, proline biosynthesis, transport processes, DNA-repair, environmental sensing,
gene regulation, and stress response. Striking examples are the occurrence of the
bacterial GroEL/GroES chaperone system and the presence of
tetrahydrofolate-dependent enzymes. These findings might indicate that lateral gene transfer has played
an important evolutionary role in forging the physiology of this metabolically
versatile methanogen.
Full article [pdf]
Copyright © 2002 Horizon Scientific Press. All Rights Reserved.
New and forthcoming molecular biology books
Recommended Reading