The fas operon of Rhodococcus fascians encodes new genes required for efficient fasciation of host plants.
Three virulence loci (fas, att, and hyp) of Rhodococcus fascians D188 have been identified on a 200-kb conjugative linear plasmid (pFiD188). The fas locus was delimited to a 6.5-kb DNA fragment by insertion mutagenesis, single homologous disruptive recombination, and in trans complementation of different avirulent insertion mutants. The locus is arranged as a large operon containing six open reading frames whose expression is specifically induced during the interaction with host plants. One predicted protein is homologous to P-450 cytochromes from actinomycetes. The putative ferredoxin component is of a novel type containing additional domains homologous to transketolases from chemoautotrophic, photosynthetic, and methylotrophic microorganisms. Genetic analysis revealed that fas encodes, in addition to the previously identified ipt, at least two new genes that are involved in fasciation development, one of which is only required on older tobacco plants.
Crespi
M
M
Laboratorium voor Genetica, Universiteit Gent, Belgium.
Vereecke
D
D
Temmerman
W
W
Van Montagu
M
M
Desomer
J
J
D019883:Alkyl and Aryl Transferases; D000595:Amino Acid Sequence; D001483:Base Sequence; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics; D004252:DNA Mutational Analysis; D005288:Ferredoxins / Q000235:genetics; D005798:Genes, Bacterial / Q000235:genetics*; D005816:Genetic Complementation Test; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D009876:Operon / Q000235:genetics*; D010947:Plants, Toxic; D012240:Rhodococcus / Q000235:genetics* / Q000472:pathogenicity*; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D014026:Nicotiana / Q000382:microbiology*; D014166:Transferases / Q000235:genetics; D014774:Virulence / Q000235:genetics
D005288:Ferredoxins; D003577:Cytochrome P-450 Enzyme System; D014166:Transferases; D019883:Alkyl and Aryl Transferases; C024274:adenylate isopentenyltransferase