title: The lethal cargo of Myxococcus xanthus outer membrane vesicles.
abstract: Myxococcus xanthus is a bacterial micro-predator known for hunting other microbes in a wolf pack-like manner. Outer membrane vesicles (OMVs) are produced in large quantities by M. xanthus and have a highly organized structure in the extracellular milieu, sometimes occurring in chains that link neighboring cells within a biofilm. OMVs may be a vehicle for mediating wolf pack activity by delivering hydrolytic enzymes and antibiotics aimed at killing prey microbes. Here, both the protein and small molecule cargo of the OMV and membrane fractions of M. xanthus were characterized and compared. Our analysis indicates a number of proteins that are OMV-specific or OMV-enriched, including several with putative hydrolytic function. Secondary metabolite profiling of OMVs identifies 16 molecules, many associated with antibiotic activities. Several hydrolytic enzyme homologs were identified, including the protein encoded by MXAN_3564 (mepA), an M36 protease homolog. Genetic disruption of mepA leads to a significant reduction in extracellular protease activity suggesting MepA is part of the long-predicted (yet to date undetermined) extracellular protease suite of M. xanthus.
authors.affiliation: Life Sciences Division, Lawrence Berkeley National Laboratory Berkeley, CA, USA ; Department of Molecular and Cell Biology, University of California, Berkeley Berkeley, CA, USA ; School of Biology, St. Mary's College Moraga, CA, USA.
authors.forename: James E
authors.initials: JE
authors.lastname: Berleman
authors.affiliation: Department of Obstetrics, Gynecology and Reproductive Science, UCSF Sandler-Moore Mass Spectrometry Core Facility San Francisco, CA, USA.
authors.forename: Simon
authors.initials: S
authors.lastname: Allen
authors.affiliation: Life Sciences Division, Lawrence Berkeley National Laboratory Berkeley, CA, USA.
authors.forename: Megan A
authors.initials: MA
authors.lastname: Danielewicz
authors.affiliation: Life Sciences Division, Lawrence Berkeley National Laboratory Berkeley, CA, USA.
authors.forename: Jonathan P
authors.initials: JP
authors.lastname: Remis
authors.affiliation: Life Sciences Division, Lawrence Berkeley National Laboratory Berkeley, CA, USA.
authors.forename: Amita
authors.initials: A
authors.lastname: Gorur
authors.affiliation: Life Sciences Division, Lawrence Berkeley National Laboratory Berkeley, CA, USA.
authors.forename: Jack
authors.initials: J
authors.lastname: Cunha
authors.affiliation: Life Sciences Division, Lawrence Berkeley National Laboratory Berkeley, CA, USA ; Space Biosciences Division, Synthetic Biology Program, NASA Ames Research Center Moffett Field, CA, USA ; Physical Biosciences Division, Lawrence Berkeley National Laboratory Berkeley, CA, USA.
authors.forename: Masood Z
authors.initials: MZ
authors.lastname: Hadi
authors.affiliation: Department of Molecular and Cell Biology, University of California, Berkeley Berkeley, CA, USA.
authors.forename: David R
authors.initials: DR
authors.lastname: Zusman
authors.affiliation: Life Sciences Division, Lawrence Berkeley National Laboratory Berkeley, CA, USA.
authors.forename: Trent R
authors.initials: TR
authors.lastname: Northen
authors.affiliation: Department of Obstetrics, Gynecology and Reproductive Science, UCSF Sandler-Moore Mass Spectrometry Core Facility San Francisco, CA, USA.
authors.forename: H Ewa
authors.initials: HE
authors.lastname: Witkowska
authors.affiliation: Life Sciences Division, Lawrence Berkeley National Laboratory Berkeley, CA, USA.
authors.forename: Manfred
authors.initials: M
authors.lastname: Auer
keywords: fruiting body; predation; predator-prey interactions; predatory rippling; secondary metabolism and enzymes