title: Agrobacterium rhizogenes GALLS protein contains domains for ATP binding, nuclear localization, and type IV secretion.
abstract: Agrobacterium tumefaciens and Agrobacterium rhizogenes are closely related plant pathogens that cause different diseases, crown gall and hairy root. Both diseases result from transfer, integration, and expression of plasmid-encoded bacterial genes located on the transferred DNA (T-DNA) in the plant genome. Bacterial virulence (Vir) proteins necessary for infection are also translocated into plant cells. Transfer of single-stranded DNA (ssDNA) and Vir proteins requires a type IV secretion system, a protein complex spanning the bacterial envelope. A. tumefaciens translocates the ssDNA-binding protein VirE2 into plant cells, where it binds single-stranded T-DNA and helps target it to the nucleus. Although some strains of A. rhizogenes lack VirE2, they are pathogenic and transfer T-DNA efficiently. Instead, these bacteria express the GALLS protein, which is essential for their virulence. The GALLS protein can complement an A. tumefaciens virE2 mutant for tumor formation, indicating that GALLS can substitute for VirE2. Unlike VirE2, GALLS contains ATP-binding and helicase motifs similar to those in TraA, a strand transferase involved in conjugation. Both GALLS and VirE2 contain nuclear localization sequences and a C-terminal type IV secretion signal. Here we show that mutations in any of these domains abolished the ability of GALLS to substitute for VirE2.
authors.affiliation: Department of Microbiology, Oregon State University, Corvallis, OR 97331, USA.
authors.forename: Larry D
authors.initials: LD
authors.lastname: Hodges
authors.forename: Annette C
authors.initials: AC
authors.lastname: Vergunst
authors.forename: Jason
authors.initials: J
authors.lastname: Neal-McKinney
authors.forename: Amke
authors.initials: A
authors.lastname: den Dulk-Ras
authors.forename: Deborah M
authors.initials: DM
authors.lastname: Moyer
authors.forename: Paul J J
authors.initials: PJ
authors.lastname: Hooykaas
authors.forename: Walt
authors.initials: W
authors.lastname: Ream
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism*; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D002467:Cell Nucleus / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism; D005816:Genetic Complementation Test; D007473:Ion Channels / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism; D008969:Molecular Sequence Data; D010935:Plant Diseases / Q000382:microbiology; D018517:Plant Roots / Q000382:microbiology; D017434:Protein Structure, Tertiary / Q000235:genetics / Q000502:physiology; D012231:Rhizobium / Q000737:chemistry*; D016415:Sequence Alignment; D015398:Signal Transduction
chemical_list: D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D007473:Ion Channels; D008565:Membrane Proteins; C051583:virE2 protein, Agrobacterium; D000255:Adenosine Triphosphate