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.
Deppenmeier
Uwe
U
Department of General Microbiology, Institute of Microbiology and Genetics, Georg-August-University, Goettingen, Germany.
Johann
Andre
A
Hartsch
Thomas
T
Merkl
Rainer
R
Schmitz
Ruth A
RA
Martinez-Arias
Rosa
R
Henne
Anke
A
Wiezer
Arnim
A
Bäumer
Sebastian
S
Jacobi
Carsten
C
Brüggemann
Holger
H
Lienard
Tanja
T
Christmann
Andreas
A
Bömeke
Mechthild
M
Steckel
Silke
S
Bhattacharyya
Anamitra
A
Lykidis
Athanasios
A
Overbeek
Ross
R
Klenk
Hans-Peter
HP
Gunsalus
Robert P
RP
Fritz
Hans-Joachim
HJ
Gottschalk
Gerhard
G
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