The composite genome of the legume symbiont Sinorhizobium meliloti.
The scarcity of usable nitrogen frequently limits plant growth. A tight metabolic association with rhizobial bacteria allows legumes to obtain nitrogen compounds by bacterial reduction of dinitrogen (N2) to ammonium (NH4+). We present here the annotated DNA sequence of the alpha-proteobacterium Sinorhizobium meliloti, the symbiont of alfalfa. The tripartite 6.7-megabase (Mb) genome comprises a 3.65-Mb chromosome, and 1.35-Mb pSymA and 1.68-Mb pSymB megaplasmids. Genome sequence analysis indicates that all three elements contribute, in varying degrees, to symbiosis and reveals how this genome may have emerged during evolution. The genome sequence will be useful in understanding the dynamics of interkingdom associations and of life in soil environments.
Galibert
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F
UMR6061-CNRS, Laboratoire de Génétique et Développement, Faculté de Médecine, 2 avenue du Pr. Léon Bernard, F-35043 Rennes cedex, France.
Finan
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Long
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Puhler
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Abola
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Ampe
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Barloy-Hubler
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Barnett
M J
MJ
Becker
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Boistard
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Bothe
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Boutry
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Bowser
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Buhrmester
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Cadieu
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Capela
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Chain
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Cowie
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Davis
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Dreano
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Federspiel
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Fisher
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Gloux
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Godrie
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Goffeau
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Golding
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Gouzy
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Gurjal
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Hernandez-Lucas
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Hong
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Huizar
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Hyman
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Jones
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Kahn
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Kahn
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Kalman
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Keating
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Kiss
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Komp
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Lelaure
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Masuy
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Palm
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Peck
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Pohl
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Portetelle
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Purnelle
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Ramsperger
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Surzycki
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Thebault
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Vandenbol
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Vorholter
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Weidner
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Wells
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Wong
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Yeh
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Batut
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D001422:Bacterial Adhesion; D001426:Bacterial Proteins / Q000235:genetics; D002352:Carrier Proteins / Q000235:genetics; D002876:Chromosomes, Bacterial / Q000235:genetics; D019295:Computational Biology; D004251:DNA Transposable Elements; D004734:Energy Metabolism / Q000235:genetics; D019143:Evolution, Molecular; D020440:Gene Duplication; D005798:Genes, Bacterial; D020043:Genes, Essential; D005809:Genes, Regulator; D016680:Genome, Bacterial; D000455:Medicago sativa / Q000382:microbiology; D009584:Nitrogen / Q000378:metabolism; D009586:Nitrogen Fixation / Q000235:genetics; D010957:Plasmids; D011135:Polysaccharides, Bacterial / Q000235:genetics; D012093:Replicon; D012230:Rhizobiaceae / Q000235:genetics; D017422:Sequence Analysis, DNA; D016962:Sinorhizobium meliloti / Q000235:genetics* / Q000502:physiology; D013559:Symbiosis / Q000235:genetics*
D001426:Bacterial Proteins; D002352:Carrier Proteins; D004251:DNA Transposable Elements; D011135:Polysaccharides, Bacterial; D009584:Nitrogen