Structural highlights
Function
BAMA_ECOLI Part of the outer membrane protein assembly complex, which is involved in assembly and insertion of beta-barrel proteins into the outer membrane. Constitutes, with BamD, the core component of the assembly machinery.[1] [2] [3] [4] [5]
Publication Abstract from PubMed
beta-barrel outer membrane proteins (beta-OMPs) play critical roles in nutrition acquisition, protein import/export, and other fundamental biological processes. The assembly of beta-OMPs in Gram-negative bacteria is mediated by the beta-barrel assembly machinery (BAM) complex, yet its precise mechanism remains elusive. Here, we report two structures of the BAM complex in detergents and in nanodisks, and two crystal structures of the BAM complex with bound substrates. Structural analysis indicates that the membrane compositions surrounding the BAM complex could modulate its overall conformations, indicating low energy barriers between different conformational states and a highly dynamic nature of the BAM complex. Importantly, structures of the BAM complex with bound substrates and the related functional analysis show that the first beta-strand of the BamA beta-barrel (beta1(BamA) ) in the BAM complex is associated with the last but not the first beta-strand of a beta-OMP substrate via antiparallel beta-strand interactions. These observations are consistent with the beta-signal hypothesis during beta-OMP biogenesis, and suggest that the beta1(BamA) strand in the BAM complex may interact with the last beta-strand of an incoming beta-OMP substrate upon their release from the chaperone-bound state.
Structures of the beta-barrel assembly machine recognizing outer membrane protein substrates.,Xiao L, Han L, Li B, Zhang M, Zhou H, Luo Q, Zhang X, Huang Y FASEB J. 2021 Jan;35(1):e21207. doi: 10.1096/fj.202001443RR. PMID:33368572[6]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Doerrler WT, Raetz CR. Loss of outer membrane proteins without inhibition of lipid export in an Escherichia coli YaeT mutant. J Biol Chem. 2005 Jul 29;280(30):27679-87. Epub 2005 Jun 10. PMID:15951436 doi:https://dx.doi.org/M504796200
- ↑ Werner J, Misra R. YaeT (Omp85) affects the assembly of lipid-dependent and lipid-independent outer membrane proteins of Escherichia coli. Mol Microbiol. 2005 Sep;57(5):1450-9. PMID:16102012 doi:https://dx.doi.org/MMI4775
- ↑ Malinverni JC, Werner J, Kim S, Sklar JG, Kahne D, Misra R, Silhavy TJ. YfiO stabilizes the YaeT complex and is essential for outer membrane protein assembly in Escherichia coli. Mol Microbiol. 2006 Jul;61(1):151-64. PMID:16824102 doi:https://dx.doi.org/10.1111/j.1365-2958.2006.05211.x
- ↑ Hagan CL, Kim S, Kahne D. Reconstitution of outer membrane protein assembly from purified components. Science. 2010 May 14;328(5980):890-2. doi: 10.1126/science.1188919. Epub 2010 Apr, 8. PMID:20378773 doi:10.1126/science.1188919
- ↑ Hagan CL, Kahne D. The reconstituted Escherichia coli Bam complex catalyzes multiple rounds of beta-barrel assembly. Biochemistry. 2011 Sep 6;50(35):7444-6. doi: 10.1021/bi2010784. Epub 2011 Aug 11. PMID:21823654 doi:10.1021/bi2010784
- ↑ Xiao L, Han L, Li B, Zhang M, Zhou H, Luo Q, Zhang X, Huang Y. Structures of the β-barrel assembly machine recognizing outer membrane protein substrates. FASEB J. 2021 Jan;35(1):e21207. PMID:33368572 doi:10.1096/fj.202001443RR
