title: Structure of the BAM complex and its implications for biogenesis of outer-membrane proteins.
abstract: In Gram-negative bacteria, the assembly of β-barrel outer-membrane proteins (OMPs) requires the β-barrel-assembly machinery (BAM) complex. We determined the crystal structure of the 200-kDa BAM complex from Escherichia coli at 3.55-Å resolution. The structure revealed that the BAM complex assembles into a hat-like shape, in which the BamA β-barrel domain forms the hat's crown embedded in the outer membrane, and its five polypeptide transport-associated (POTRA) domains interact with the four lipoproteins BamB, BamC, BamD and BamE, thus forming the hat's brim in the periplasm. The assembly of the BAM complex creates a ring-like apparatus beneath the BamA β-barrel in the periplasm and a potential substrate-exit pore located at the outer membrane-periplasm interface. The complex structure suggests that the chaperone-bound OMP substrates may feed into the chamber of the ring-like apparatus and insert into the outer membrane via the potential substrate-exit pore in an energy-independent manner.
authors.affiliation: National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.|University of Chinese Academy of Sciences, Beijing, China.
authors.forename: Long
authors.initials: L
authors.lastname: Han
authors.affiliation: National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.
authors.forename: Jiangge
authors.initials: J
authors.lastname: Zheng
authors.affiliation: National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Wang
authors.affiliation: National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.
authors.forename: Xu
authors.initials: X
authors.lastname: Yang
authors.affiliation: National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.|University of Chinese Academy of Sciences, Beijing, China.
authors.forename: Yanqing
authors.initials: Y
authors.lastname: Liu
authors.affiliation: National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.|University of Chinese Academy of Sciences, Beijing, China.
authors.forename: Chuanqi
authors.initials: C
authors.lastname: Sun
authors.affiliation: National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.
authors.forename: Baohua
authors.initials: B
authors.lastname: Cao
authors.affiliation: National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.
authors.forename: Haizhen
authors.initials: H
authors.lastname: Zhou
authors.affiliation: National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.
authors.forename: Dongchun
authors.initials: D
authors.lastname: Ni
authors.affiliation: Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.
authors.forename: Jizhong
authors.initials: J
authors.lastname: Lou
authors.affiliation: National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.
authors.forename: Yongfang
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.
authors.forename: Yihua
authors.initials: Y
authors.lastname: Huang
mesh_terms: D001425:Bacterial Outer Membrane Proteins / Q000378:metabolism*; D018360:Crystallography, X-Ray; D004926:Escherichia coli / Q000737:chemistry* / Q000201:enzymology*; D008958:Models, Molecular; D009097:Multienzyme Complexes / Q000737:chemistry* / Q000378:metabolism*; D011487:Protein Conformation
chemical_list: D001425:Bacterial Outer Membrane Proteins; D009097:Multienzyme Complexes