3PRW

Crystal structure of the lipoprotein BamB

3PRW の概要

• エントリーDOI: 10.2210/pdb3prw/pdb
• 分子名称: Lipoprotein yfgL (2 entities in total)
• 機能のキーワード: beta propeller, structural protein
• 由来する生物種: Escherichia coli
• 細胞内の位置: Cell outer membrane ; Lipid-anchor : P77774
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 40190.69

構造登録者

Heuck, A.,Clausen, T. (登録日: 2010-11-30, 公開日: 2011-01-19, 最終更新日: 2024-02-21)

主引用文献

Heuck, A.,Schleiffer, A.,Clausen, T.
Augmenting beta-augmentation: structural basis of how BamB binds BamA and may support folding of outer membrane proteins.
J.Mol.Biol., 406:659-666, 2011

PubMed Abstract: β-Barrel proteins are frequently found in the outer membrane of mitochondria, chloroplasts and Gram-negative bacteria. In Escherichia coli, these proteins are inserted in the outer membrane by the Bam (β-barrel assembly machinery) complex, a multiprotein machinery formed by the β-barrel protein BamA and the four peripheral membrane proteins BamB, BamC, BamD and BamE. The periplasmic part of BamA binds prefolded β-barrel proteins by a β-augmentation mechanism, thereby stabilizing the precursors prior to their membrane insertion. However, the role of the associated proteins within the Bam complex remains unknown. Here, we describe the crystal structure of BamB, a nonessential component of the Bam complex. The structure shows a typical eight-bladed β-propeller fold. Two sequence stretches of BamB were previously identified to be important for interaction with BamA. In our structure, both motifs are located in close proximity to each other and contribute to a conserved region forming a narrow groove on the top of the propeller. Moreover, crystal contacts reveal two interaction modes of how BamB might bind unfolded β-barrel proteins. In the crystal lattice, BamB binds to exposed β-strands by β-augmentation, whereas peptide stretches rich in aromatic residues can be accommodated in hydrophobic pockets located at the bottom of the propeller. Thus, BamB could simultaneously bind to BamA and prefolded β-barrel proteins, thereby enhancing the folding and membrane insertion capability of the Bam complex.

PubMed: 21236263
DOI: 10.1016/j.jmb.2011.01.002

実験手法

X-RAY DIFFRACTION (1.8 Å)