attG and attC mutations of Agrobacterium tumefaciens are dominant negative mutations that block attachment and virulence.
The cryptic plasmid (pAT) of Agrobacterium tumefaciens was not required for virulence or attachment to plant surfaces. However, mutations in the attC and attG genes located on pAT caused the bacteria to become avirulent and non-attaching on tomato, carrot, and Bryophyllum daigremontiana. This was the case whether the mutation was in the copy of the genes located on pAT or whether it was carried in a second copy of the attA-G operon located on a plasmid in cells that contained a wild-type copy of pAT. Thus attC and attG mutations are dominant negative mutations. The mechanism by which these mutations block attachment and virulence is unknown.
Matthysse
Ann G
AG
Department of Biology, University of North Carolina, Coker Hall, Chapel Hill, NC 27599-3280, USA. ann_matthysse@unc.edu
Jaeckel
Peter
P
Jeter
Cecelia
C
D018528:ATP-Binding Cassette Transporters / Q000235:genetics*; D016960:Agrobacterium tumefaciens / Q000235:genetics / Q000472:pathogenicity* / Q000502:physiology; D001422:Bacterial Adhesion; D001426:Bacterial Proteins / Q000235:genetics*; D018552:Daucus carota / Q000382:microbiology; D005799:Genes, Dominant; D018551:Solanum lycopersicum / Q000382:microbiology; D009154:Mutation; D009876:Operon; D018517:Plant Roots / Q000382:microbiology; D010941:Plant Tumors / Q000382:microbiology*; D010957:Plasmids; D014774:Virulence
D018528:ATP-Binding Cassette Transporters; D001426:Bacterial Proteins