A modular BAM complex in the outer membrane of the alpha-proteobacterium Caulobacter crescentus.
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.
Anwari
Khatira
K
Department of Biochemistry and Molecular Biology, Monash University, Melbourne, Australia.
Poggio
Sebastian
S
Perry
Andrew
A
Gatsos
Xenia
X
Ramarathinam
Sri Harsha
SH
Williamson
Nicholas A
NA
Noinaj
Nicholas
N
Buchanan
Susan
S
Gabriel
Kipros
K
Purcell
Anthony W
AW
Jacobs-Wagner
Christine
C
Lithgow
Trevor
T
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
D001425:Bacterial Outer Membrane Proteins; D017931:DNA Primers