The genome sequence of the tomato-pathogenic actinomycete Clavibacter michiganensis subsp. michiganensis NCPPB382 reveals a large island involved in pathogenicity.
Clavibacter michiganensis subsp. michiganensis is a plant-pathogenic actinomycete that causes bacterial wilt and canker of tomato. The nucleotide sequence of the genome of strain NCPPB382 was determined. The chromosome is circular, consists of 3.298 Mb, and has a high G+C content (72.6%). Annotation revealed 3,080 putative protein-encoding sequences; only 26 pseudogenes were detected. Two rrn operons, 45 tRNAs, and three small stable RNA genes were found. The two circular plasmids, pCM1 (27.4 kbp) and pCM2 (70.0 kbp), which carry pathogenicity genes and thus are essential for virulence, have lower G+C contents (66.5 and 67.6%, respectively). In contrast to the genome of the closely related organism Clavibacter michiganensis subsp. sepedonicus, the genome of C. michiganensis subsp. michiganensis lacks complete insertion elements and transposons. The 129-kb chp/tomA region with a low G+C content near the chromosomal origin of replication was shown to be necessary for pathogenicity. This region contains numerous genes encoding proteins involved in uptake and metabolism of sugars and several serine proteases. There is evidence that single genes located in this region, especially genes encoding serine proteases, are required for efficient colonization of the host. Although C. michiganensis subsp. michiganensis grows mainly in the xylem of tomato plants, no evidence for pronounced genome reduction was found. C. michiganensis subsp. michiganensis seems to have as many transporters and regulators as typical soil-inhabiting bacteria. However, the apparent lack of a sulfate reduction pathway, which makes C. michiganensis subsp. michiganensis dependent on reduced sulfur compounds for growth, is probably the reason for the poor survival of C. michiganensis subsp. michiganensis in soil.
Gartemann
Karl-Heinz
KH
Lehrstuhl für Gentechnologie/Mikrobiologie, Universität Bielefeld, D-33501 Bielefeld, Germany.
Abt
Birte
B
Bekel
Thomas
T
Burger
Annette
A
Engemann
Jutta
J
Flügel
Monika
M
Gaigalat
Lars
L
Goesmann
Alexander
A
Gräfen
Ines
I
Kalinowski
Jörn
J
Kaup
Olaf
O
Kirchner
Oliver
O
Krause
Lutz
L
Linke
Burkhard
B
McHardy
Alice
A
Meyer
Folker
F
Pohle
Sandra
S
Rückert
Christian
C
Schneiker
Susanne
S
Zellermann
Eva-Maria
EM
Pühler
Alfred
A
Eichenlaub
Rudolf
R
Kaiser
Olaf
O
Bartels
Daniela
D
D039903:Actinobacteria / Q000235:genetics* / Q000472:pathogenicity; D001482:Base Composition / Q000235:genetics; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics*; D016521:Electrophoresis, Gel, Pulsed-Field; D005798:Genes, Bacterial / Q000235:genetics; D016680:Genome, Bacterial; D044404:Genomic Islands / Q000235:genetics; D018551:Solanum lycopersicum / Q000382:microbiology*; D008957:Models, Genetic; D008969:Molecular Sequence Data; D009876:Operon / Q000235:genetics; D010957:Plasmids / Q000235:genetics; D017422:Sequence Analysis, DNA; D012697:Serine Endopeptidases / Q000235:genetics
D004269:DNA, Bacterial; D012697:Serine Endopeptidases