title: Association of the Agrobacterium T-DNA-protein complex with plant nucleosomes.
abstract: Agrobacterium represents the only natural example of transkingdom transfer of genetic information, from bacteria to plants. Before the bacterial transferred DNA (T-DNA) can integrate into the plant genome, it should be targeted to and bind the host chromatin. However, the T-DNA association with the host chromatin has not been demonstrated. Here, we study T-DNA binding to plant nucleosomes in vitro and show that it is mediated by bacterial and host proteins associated with the T-DNA. The main factor that determines nucleosomal binding of the T-DNA is the cellular VirE2-interacting protein 1 (VIP1), which functions as a molecular link between the T-DNA-associated bacterial virulence protein VirE2 and core histones. The presence of both VIP1 and VirE2 is required for association of the T-DNA with mononucleosomes in which the DNA molecule exists as a tripartite complex DNA-VirE2-VIP1. Furthermore, this nucleosome-associated ternary complex can bind another bacterial virulence factor, VirF, which is an F-box protein known to target both VirE2 and VIP1 for proteasomal degradation and uncoat the T-DNA.
authors.affiliation: Department of Biochemistry and Cell Biology, State University of New York, Stony Brook, NY 11794-5215, USA.
authors.forename: Benoît
authors.initials: B
authors.lastname: Lacroix
authors.forename: Abraham
authors.initials: A
authors.lastname: Loyter
authors.forename: Vitaly
authors.initials: V
authors.lastname: Citovsky
mesh_terms: D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001665:Binding Sites; D004269:DNA, Bacterial / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D007473:Ion Channels / Q000235:genetics / Q000378:metabolism; D009707:Nucleosomes / Q000378:metabolism*; D010944:Plants / Q000382:microbiology*; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D012231:Rhizobium / Q000235:genetics* / Q000378:metabolism; D037521:Virulence Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; D007473:Ion Channels; D009707:Nucleosomes; C036483:T-DNA; C432104:VIP1 protein, Arabidopsis; D037521:Virulence Factors; C051583:virE2 protein, Agrobacterium; D046988:Proteasome Endopeptidase Complex