scholarly journals Simulation Studies of Transport of Hydrophobic Compounds through Outer Membrane Proteins of Gram Negative Bacteria

2012 ◽  
Vol 102 (3) ◽  
pp. 430a-431a
Author(s):  
Pragya Chohan ◽  
Syma Khalid ◽  
Mark Sansom
Keyword(s):  
Membrane Proteins ◽  
Outer Membrane ◽  
Outer Membrane Proteins ◽  
Gram Negative Bacteria ◽  
Simulation Studies ◽  
Gram Negative ◽  
Hydrophobic Compounds

scholarly journals Functions of the BamBCDE Lipoproteins Revealed by Bypass Mutations in BamA

2020 ◽  
Vol 202 (21) ◽  
Author(s):  
Elizabeth M. Hart ◽  
Thomas J. Silhavy
Keyword(s):  
Membrane Proteins ◽  
Outer Membrane ◽  
Outer Membrane Proteins ◽  
Gram Negative Bacteria ◽  
Wild Type ◽  
Gram Negative ◽  
Bam Complex ◽  
Essential Function ◽  
The Individual

ABSTRACT The heteropentomeric β-barrel assembly machine (BAM complex) is responsible for folding and inserting a diverse array of β-barrel outer membrane proteins (OMPs) into the outer membrane (OM) of Gram-negative bacteria. The BAM complex contains two essential proteins, the β-barrel OMP BamA and a lipoprotein BamD, whereas the auxiliary lipoproteins BamBCE are individually nonessential. Here, we identify and characterize three bamA mutations, the E-to-K change at position 470 (bamAE470K), the A-to-P change at position 496 (bamAA496P), and the A-to-S change at position 499 (bamAA499S), that suppress the otherwise lethal ΔbamD, ΔbamB ΔbamC ΔbamE, and ΔbamC ΔbamD ΔbamE mutations. The viability of cells lacking different combinations of BAM complex lipoproteins provides the opportunity to examine the role of the individual proteins in OMP assembly. Results show that, in wild-type cells, BamBCE share a redundant function; at least one of these lipoproteins must be present to allow BamD to coordinate productively with BamA. Besides BamA regulation, BamD shares an additional essential function that is redundant with a second function of BamB. Remarkably, bamAE470K suppresses both, allowing the construction of a BAM complex composed solely of BamAE470K that is able to assemble OMPs in the absence of BamBCDE. This work demonstrates that the BAM complex lipoproteins do not participate in the catalytic folding of OMP substrates but rather function to increase the efficiency of the assembly process by coordinating and regulating the assembly of diverse OMP substrates. IMPORTANCE The folding and insertion of β-barrel outer membrane proteins (OMPs) are conserved processes in mitochondria, chloroplasts, and Gram-negative bacteria. In Gram-negative bacteria, OMPs are assembled into the outer membrane (OM) by the heteropentomeric β-barrel assembly machine (BAM complex). In this study, we probe the function of the individual BAM proteins and how they coordinate assembly of a diverse family of OMPs. Furthermore, we identify a gain-of-function bamA mutant capable of assembling OMPs independently of all four other BAM proteins. This work advances our understanding of OMP assembly and sheds light on how this process is distinct in Gram-negative bacteria.

scholarly journals Assembly of the β-Barrel Outer Membrane Proteins in Gram-Negative Bacteria, Mitochondria, and Chloroplasts

2012 ◽  
Vol 2012 ◽  
pp. 1-15 ◽  
Author(s):  
Rajeev Misra
Keyword(s):  
Membrane Proteins ◽  
Outer Membrane ◽  
Protein Interactions ◽  
Structural Information ◽  
Outer Membrane Proteins ◽  
Model Systems ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
The Core ◽  
Assembly Pathways

In the last decade, there has been an explosion of publications on the assembly of β-barrel outer membrane proteins (OMPs), which carry out diverse cellular functions, including solute transport, protein secretion, and assembly of protein and lipid components of the outer membrane. Of the three outer membrane model systems—Gram-negative bacteria, mitochondria and chloroplasts—research on bacterial and mitochondrial systems has so far led the way in dissecting the β-barrel OMP assembly pathways. Many exciting discoveries have been made, including the identification of β-barrel OMP assembly machineries in bacteria and mitochondria, and potentially the core assembly component in chloroplasts. The atomic structures of all five components of the bacterial β-barrel assembly machinery (BAM) complex, except the β-barrel domain of the core BamA protein, have been solved. Structures reveal that these proteins contain domains/motifs known to facilitate protein-protein interactions, which are at the heart of the assembly pathways. While structural information has been valuable, most of our current understanding of the β-barrel OMP assembly pathways has come from genetic, molecular biology, and biochemical analyses. This paper provides a comparative account of the β-barrel OMP assembly pathways in Gram-negative bacteria, mitochondria, and chloroplasts.

Design and Production of Hybrid Antigens for Targeting Integral Outer Membrane Proteins in Gram-Negative Bacteria

2021 ◽  
pp. 115-140
Author(s):  
Somshukla Chaudhuri ◽  
Nikolas F. Ewasechko ◽  
Luisa Samaniego-Barron ◽  
Jamie E. Fegan ◽  
Anthony B. Schryvers
Keyword(s):  
Membrane Proteins ◽  
Outer Membrane ◽  
Outer Membrane Proteins ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Design And Production

scholarly journals OMPdb: a database of  -barrel outer membrane proteins from Gram-negative bacteria

2010 ◽  
Vol 39 (Database) ◽  
pp. D324-D331 ◽  
Author(s):  
K. D. Tsirigos ◽  
P. G. Bagos ◽  
S. J. Hamodrakas
Keyword(s):  
Membrane Proteins ◽  
Outer Membrane ◽  
Outer Membrane Proteins ◽  
Gram Negative Bacteria ◽  
Gram Negative
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