title: Localization of the protein VirB1 involved in contact formation during conjugation among Agrobacterium cells.
abstract: Supramembrane structures of Agrobacterium, which link cells during mating, were for the first time visualized using transmission electron microscopy. The initial cell contact was found to be mediated by long pili. Using colloidal gold-labeled, VirB1-specific antibodies, it was established that VirB1 proteins enter into the composition of short pilus-like structures, which emerge at the poles of acetosyringone (AS)-induced agrobacterial cells. Labeling of non-centrifuged agrobacterial cells on a nitrocellulose membrane using colloidal gold-conjugated antibodies to VirB1 showed that the labeled complex could bind to AS-induced cells, but failed to form red stains during incubation with cells of the Ti plasmidless A. tumefaciens strains LBA288 and UBAPF-2.
authors.affiliation: Institute of Biochemistry and Physiology of Plants and Microorganisms, Russian Academy of Sciences, Saratov, Russia. chumakov@ibppm.saratov.su
authors.forename: M I
authors.initials: MI
authors.lastname: Chumakov
authors.forename: I V
authors.initials: IV
authors.lastname: Kurbanova
mesh_terms: D000907:Antibodies, Bacterial / Q000276:immunology; D001426:Bacterial Proteins / Q000032:analysis* / Q000235:genetics / Q000276:immunology; D003227:Conjugation, Genetic; D010861:Fimbriae, Bacterial / Q000737:chemistry*; D017979:Gold Colloid; D008854:Microscopy, Electron; D016253:Microscopy, Immunoelectron; D010957:Plasmids; D012231:Rhizobium / Q000737:chemistry / Q000235:genetics* / Q000648:ultrastructure; D037521:Virulence Factors
chemical_list: D000907:Antibodies, Bacterial; D001426:Bacterial Proteins; D017979:Gold Colloid; D037521:Virulence Factors