title: Quantitative image analysis and modeling indicate the Agrobacterium tumefaciens type IV secretion system is organized in a periodic pattern of foci.
abstract: The Gram negative plant pathogen Agrobacterium tumefaciens is uniquely capable of genetically transforming eukaryotic host cells during the infection process. DNA and protein substrates are transferred into plant cells via a type IV secretion system (T4SS), which forms large cell-envelope spanning complexes at multiple sites around the bacterial circumference. To gain a detailed understanding of T4SS positioning, the spatial distribution of fluorescently labeled T4SS components was quantitatively assessed to distinguish between random and structured localization processes. Through deconvolution microscopy followed by Fourier analysis and modeling, T4SS foci were found to localize in a non-random periodic pattern. These results indicate that T4SS complexes are dependent on an underlying scaffold or assembly process to obtain an organized distribution suitable for effective delivery of substrates into host cells.
authors.affiliation: Department of Plant and Microbial Biology, University of California, Berkeley, California, United States of America.
authors.forename: Todd A
authors.initials: TA
authors.lastname: Cameron
authors.forename: Marcus
authors.initials: M
authors.lastname: Roper
authors.forename: Patricia C
authors.initials: PC
authors.lastname: Zambryski
mesh_terms: D016960:Agrobacterium tumefaciens / Q000235:genetics / Q000502:physiology*; D001426:Bacterial Proteins / Q000502:physiology*; D004269:DNA, Bacterial / Q000502:physiology*; D008962:Models, Theoretical
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial