nanopods a new bacterial structure and mechanism for deployment of outer membrane vesiclesnanopods新细菌外膜囊泡的结构和部署机制.pdfVIP

Nanopods: A New Bacterial Structure and Mechanism for Deployment of Outer Membrane Vesicles 1 2 3 3,4 1,2 Ameesha Shetty , Shicheng Chen , Elitza I. Tocheva , Grant J. Jensen , William J. Hickey * 1 Molecular and Environmental Toxicology Program, University of Wisconsin-Madison, Madison, Wisconsin, United States of America, 2 O.N. Allen Laboratory for Soil Microbiology, Department of Soil Science, University of Wisconsin-Madison, Madison, Wisconsin, United States of America, 3 Division of Biology, California Institute of Technology, Pasadena, California, United States of America, 4 Howard Hughes Medical Institute, California Institute of Technology, Pasadena, California, United States of America Abstract Background: Bacterial outer membrane vesicles (OMV) are packets of periplasmic material that, via the proteins and other molecules they contain, project metabolic function into the environment. While OMV production is widespread in proteobacteria, they have been extensively studied only in pathogens, which inhabit fully hydrated environments. However, many (arguably most) bacterial habitats, such as soil, are only partially hydrated. In the latter, water is characteristically distributed as films on soil particles that are, on average thinner, than are typical OMV (ca. #10 nm water film vs. 20 to .200 nm OMV;). Methodology/Principal Findings: We have identified a new bacterial surface structure, termed a ‘‘nanopod’’, that is a conduit for projecting OMV significant distances (e.g., $6 mm) from the cell. Electron cryotomography was used to determine nanopod three-dimension