β-Lactamase expression and outer membrane protein changes in cefpirome-resistant and ceftazidime-resistant Gram-negative bacteria

1991 ◽  
Vol 28 (2) ◽  
pp. 209-219 ◽  
Author(s):  
Laura J. V. Piddock ◽  
E. A. Traynor
Keyword(s):  
Membrane Protein ◽  
Outer Membrane ◽  
Outer Membrane Protein ◽  
Gram Negative Bacteria ◽  
Gram Negative

scholarly journals TP0453, a Concealed Outer Membrane Protein of Treponema pallidum, Enhances Membrane Permeability

2005 ◽  
Vol 187 (18) ◽  
pp. 6499-6508 ◽  
Author(s):  
Karsten R. O. Hazlett ◽  
David L. Cox ◽  
Marc Decaffmeyer ◽  
Michael P. Bennett ◽  
Daniel C. Desrosiers ◽  
...  
Keyword(s):  
Membrane Protein ◽  
Outer Membrane ◽  
Outer Membrane Protein ◽  
Outer Membrane Proteins ◽  
Nutrient Transport ◽  
Treponema Pallidum ◽  
Protein S ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Membrane Spanning

ABSTRACT The outer membrane of Treponema pallidum, the noncultivable agent of venereal syphilis, contains a paucity of protein(s) which has yet to be definitively identified. In contrast, the outer membranes of gram-negative bacteria contain abundant immunogenic membrane-spanning β-barrel proteins mainly involved in nutrient transport. The absence of orthologs of gram-negative porins and outer membrane nutrient-specific transporters in the T. pallidum genome predicts that nutrient transport across the outer membrane must differ fundamentally in T. pallidum and gram-negative bacteria. Here we describe a T. pallidum outer membrane protein (TP0453) that, in contrast to all integral outer membrane proteins of known structure, lacks extensive β-sheet structure and does not traverse the outer membrane to become surface exposed. TP0453 is a lipoprotein with an amphiphilic polypeptide containing multiple membrane-inserting, amphipathic α-helices. Insertion of the recombinant, nonlipidated protein into artificial membranes results in bilayer destabilization and enhanced permeability. Our findings lead us to hypothesize that TP0453 is a novel type of bacterial outer membrane protein which may render the T. pallidum outer membrane permeable to nutrients while remaining inaccessible to antibody.

scholarly journals Assembly and Channel Opening of Outer Membrane Protein in Tripartite Drug Efflux Pumps of Gram-negative Bacteria

2012 ◽  
Vol 287 (15) ◽  
pp. 11740-11750 ◽  
Author(s):  
Yongbin Xu ◽  
Arne Moeller ◽  
So-Young Jun ◽  
Minho Le ◽  
Bo-Young Yoon ◽  
...  
Keyword(s):  
Membrane Protein ◽  
Fusion Protein ◽  
Membrane Fusion ◽  
Outer Membrane ◽  
Outer Membrane Protein ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Membrane Fusion Protein ◽  
Docking Model ◽  
Channel Opening

Gram-negative bacteria are capable of expelling diverse xenobiotic substances from within the cell by use of three-component efflux pumps in which the energy-activated inner membrane transporter is connected to the outer membrane channel protein via the membrane fusion protein. In this work, we describe the crystal structure of the membrane fusion protein MexA from the Pseudomonas aeruginosa MexAB-OprM pump in the hexameric ring arrangement. Electron microscopy study on the chimeric complex of MexA and the outer membrane protein OprM reveals that MexA makes a tip-to-tip interaction with OprM, which suggests a docking model for MexA and OprM. This docking model agrees well with genetic results and depicts detailed interactions. Opening of the OprM channel is accompanied by the simultaneous exposure of a protein structure resembling a six-bladed cogwheel, which intermeshes with the complementary cogwheel structure in the MexA hexamer. Taken together, we suggest an assembly and channel opening model for the MexAB-OprM pump. This study provides a better understanding of multidrug resistance in Gram-negative bacteria.

scholarly journals Serum Amyloid A Protein Binds to Outer Membrane Protein A of Gram-negative Bacteria

2005 ◽  
Vol 280 (19) ◽  
pp. 18562-18567 ◽  
Author(s):  
Ranjeeta Hari-Dass ◽  
Chandrabala Shah ◽  
David J. Meyer ◽  
John G. Raynes
Keyword(s):  
Membrane Protein ◽  
Outer Membrane ◽  
Outer Membrane Protein ◽  
Serum Amyloid A ◽  
Protein A ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Amyloid A ◽  
Serum Amyloid A Protein ◽  
Outer Membrane Protein A

Structure and functions of bacterial outer membrane protein A, a potential therapeutic target for bacterial infection

2021 ◽  
Vol 21 ◽  
Author(s):  
Qingfeng Guan ◽  
Biswajit Bhowmick ◽  
Archana Upadhyay ◽  
Qian Han
Keyword(s):  
Membrane Protein ◽  
Bacterial Infection ◽  
Outer Membrane ◽  
Outer Membrane Protein ◽  
Therapeutic Target ◽  
Protein A ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Outer Membrane Protein A ◽  
Structure And Functions

: Outer membrane protein A (OmpA) is a unique outer membrane protein which is abundantly present in the outer membrane of Gram‐negative bacteria. OmpA is a transmembrane structural protein with a conserved amino acid sequence among different bacteria. This protein is involved in a number of functions like adhesion, toxicity, invasiveness, and biofilm formation in Gram-negative bacteria. Many studies have proposed that OmpA could be a therapeutic target for bacterial infection. Our review focusses on the studies involving recent development in the structure and functions of OmpA and further discussing its potential as a therapeutic target for bacterial infection.

scholarly journals Formation of a β-barrel membrane protein is catalyzed by the interior surface of the assembly machine protein BamA

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
James Lee ◽  
David Tomasek ◽  
Thiago MA Santos ◽  
Mary D May ◽  
Ina Meuskens ◽  
...  
Keyword(s):  
Membrane Protein ◽  
Outer Membrane ◽  
Molecular Mechanisms ◽  
Gram Negative Bacteria ◽  
Site Specific ◽  
Gram Negative ◽  
Interior Surface ◽  
Essential Component ◽  
Bam Complex ◽  
Β Sheet

The β-barrel assembly machine (Bam) complex in Gram-negative bacteria and its counterparts in mitochondria and chloroplasts fold and insert outer membrane β-barrel proteins. BamA, an essential component of the complex, is itself a β-barrel and is proposed to play a central role in assembling other barrel substrates. Here, we map the path of substrate insertion by the Bam complex using site-specific crosslinking to understand the molecular mechanisms that control β-barrel folding and release. We find that the C-terminal strand of the substrate is stably held by BamA and that the N-terminal strands of the substrate are assembled inside the BamA β-barrel. Importantly, we identify contacts between the assembling β-sheet and the BamA interior surface that determine the rate of substrate folding. Our results support a model in which the interior wall of BamA acts as a chaperone to catalyze β-barrel assembly.

scholarly journals The essential inner membrane protein YejM is a metalloenzyme

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Uma Gabale ◽  
Perla Arianna Peña Palomino ◽  
HyunAh Kim ◽  
Wenya Chen ◽  
Susanne Ressl
Keyword(s):  
Antibiotic Resistance ◽  
Membrane Protein ◽  
Outer Membrane ◽  
Critical Role ◽  
Membrane Properties ◽  
Gram Negative Bacteria ◽  
Inner Membrane ◽  
Gram Negative ◽  
Periplasmic Domain ◽  
Inner Membrane Protein

Abstract Recent recurrent outbreaks of Gram-negative bacteria show the critical need to target essential bacterial mechanisms to fight the increase of antibiotic resistance. Pathogenic Gram-negative bacteria have developed several strategies to protect themselves against the host immune response and antibiotics. One such strategy is to remodel the outer membrane where several genes are involved. yejM was discovered as an essential gene in E. coli and S. typhimurium that plays a critical role in their virulence by changing the outer membrane permeability. How the inner membrane protein YejM with its periplasmic domain changes membrane properties remains unknown. Despite overwhelming structural similarity between the periplasmic domains of two YejM homologues with hydrolases like arylsulfatases, no enzymatic activity has been previously reported for YejM. Our studies reveal an intact active site with bound metal ions in the structure of YejM periplasmic domain. Furthermore, we show that YejM has a phosphatase activity that is dependent on the presence of magnesium ions and is linked to its function of regulating outer membrane properties. Understanding the molecular mechanism by which YejM is involved in outer membrane remodeling will help to identify a new drug target in the fight against the increased antibiotic resistance.

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