title: A modular BAM complex in the outer membrane of the alpha-proteobacterium Caulobacter crescentus.
abstract: Mitochondria are organelles derived from an intracellular alpha-proteobacterium. The biogenesis of mitochondria relies on the assembly of beta-barrel proteins into the mitochondrial outer membrane, a process inherited from the bacterial ancestor. Caulobacter crescentus is an alpha-proteobacterium, and the BAM (beta-barrel assembly machinery) complex was purified and characterized from this model organism. Like the mitochondrial sorting and assembly machinery complex, we find the BAM complex to be modular in nature. A approximately 150 kDa core BAM complex containing BamA, BamB, BamD, and BamE associates with additional modules in the outer membrane. One of these modules, Pal, is a lipoprotein that provides a means for anchorage to the peptidoglycan layer of the cell wall. We suggest the modular design of the BAM complex facilitates access to substrates from the protein translocase in the inner membrane.
authors.affiliation: Department of Biochemistry and Molecular Biology, Monash University, Melbourne, Australia.
authors.forename: Khatira
authors.initials: K
authors.lastname: Anwari
authors.forename: Sebastian
authors.initials: S
authors.lastname: Poggio
authors.forename: Andrew
authors.initials: A
authors.lastname: Perry
authors.forename: Xenia
authors.initials: X
authors.lastname: Gatsos
authors.forename: Sri Harsha
authors.initials: SH
authors.lastname: Ramarathinam
authors.forename: Nicholas A
authors.initials: NA
authors.lastname: Williamson
authors.forename: Nicholas
authors.initials: N
authors.lastname: Noinaj
authors.forename: Susan
authors.initials: S
authors.lastname: Buchanan
authors.forename: Kipros
authors.initials: K
authors.lastname: Gabriel
authors.forename: Anthony W
authors.initials: AW
authors.lastname: Purcell
authors.forename: Christine
authors.initials: C
authors.lastname: Jacobs-Wagner
authors.forename: Trevor
authors.initials: T
authors.lastname: Lithgow
mesh_terms: D000595:Amino Acid Sequence; D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry / Q000378:metabolism*; D001483:Base Sequence; D016935:Caulobacter crescentus / Q000378:metabolism*; D017931:DNA Primers; D004591:Electrophoresis, Polyacrylamide Gel; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid
chemical_list: D001425:Bacterial Outer Membrane Proteins; D017931:DNA Primers