The genome of Methanosarcina mazei: evidence for lateral gene transfer between bacteria and archaea.
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 gluconeogenesis, 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.
Department of General Microbiology, Institute of Microbiology and Genetics, Georg-August-University, Goettingen, Germany.
Uwe
U
Deppenmeier
Andre
A
Johann
Thomas
T
Hartsch
Rainer
R
Merkl
Ruth A
RA
Schmitz
Rosa
R
Martinez-Arias
Anke
A
Henne
Arnim
A
Wiezer
Sebastian
S
Bäumer
Carsten
C
Jacobi
Holger
H
Brüggemann
Tanja
T
Lienard
Andreas
A
Christmann
Mechthild
M
Bömeke
Silke
S
Steckel
Anamitra
A
Bhattacharyya
Athanasios
A
Lykidis
Ross
R
Overbeek
Hans-Peter
HP
Klenk
Robert P
RP
Gunsalus
Hans-Joachim
HJ
Fritz
Gerhard
G
Gottschalk
D001105:Archaea / Q000235:genetics*; D001419:Bacteria / Q000145:classification / Q000235:genetics*; D018014:Gene Transfer Techniques; D020745:Genome, Archaeal; D017020:Methanosarcina / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D016366:Open Reading Frames; D010802:Phylogeny