scholarly journals Towards understanding the molecular mechanism of cardiolipin transport in Salmonella typhimurium: interactions between an essential inner membrane protein YejM and its newly found ligand, YejL

F1000Research ◽  
2016 ◽  
Vol 5 ◽  
pp. 1086 ◽  
Author(s):  
Uma Gabale ◽  
Gene Qian ◽  
Elaina Roach ◽  
Susanne Ressl
Keyword(s):  
Membrane Protein ◽  
Drug Targets ◽  
Essential Gene ◽  
The United States ◽  
X Ray Diffraction ◽  
Inner Membrane ◽  
Its Gene ◽  
Inner Membrane Protein ◽  
First Time

Salmonella typhimurium is responsible for over 35% of all foodborne illness related hospitalizations in the United States. This Gram-negative bacterium possesses an inner and an outer membrane (OM), the latter allowing its survival and replication within host tissues. During infection, OM is remodeled by transport of glycerophospholipids across the periplasm and into the OM. Increased levels of cardiolipin in the OM were observed upon PhoPQ activation and led to the discovery of YejM; an inner membrane protein essential for cell growth involved in cardiolipin binding and transport to the OM. Another protein that might be playing a role in cardiolipin transport is YejL, as its gene is localized upstream of yejm on the same operon. Here we report how YejM was engineered to facilitate crystal growth and X-ray diffraction analysis. Furthermore, we present for the first time that YejL is a ligand for YejM. Successful structure determination of YejM and YejL will help us understand how they interact and how YejM facilitates cardiolipin transport to the OM. Ultimately, yejm, being an essential gene, may lead to new drug targets inhibiting the pathogenic properties of S. typhimurium.

scholarly journals Crystallization and preliminary X-ray diffraction analysis of YejM from Salmonella typhimurium: an essential inner membrane protein involved in outer membrane directed cardiolipin transport

F1000Research ◽  
2017 ◽  
Vol 5 ◽  
pp. 1086
Author(s):  
Uma Gabale ◽  
Gene Qian ◽  
Elaina Roach ◽  
Susanne Ressl
Keyword(s):  
Membrane Protein ◽  
Diffraction Analysis ◽  
Outer Membrane ◽  
Drug Targets ◽  
Essential Gene ◽  
The United States ◽  
X Ray Diffraction ◽  
Inner Membrane ◽  
X Ray ◽  
Inner Membrane Protein

Salmonella  typhimurium is responsible for over 35% of all foodborne illness related hospitalizations in the United States. This Gram-negative bacterium possesses an inner and an outer membrane (OM), the latter allowing its survival and replication within host tissues. During infection, OM is remodeled by transport of glycerophospholipids across the periplasm and into the OM. Increased levels of cardiolipin in the OM were observed upon PhoPQ activation and led to the discovery of YejM; an inner membrane protein essential for cell growth involved in cardiolipin binding and transport to the OM. Here we report how YejM was engineered to facilitate crystal growth and X-ray diffraction analysis. Successful structure determination of YejM will help us understand how they interact and how YejM facilitates cardiolipin transport to the OM. Ultimately, yejm, being an essential gene, may lead to new drug targets inhibiting the pathogenic properties of S. typhimurium.

scholarly journals New functional identity of the essential inner membrane protein YejM: the cardiolipin translocator is also a metalloenzyme

2020 ◽  
Author(s):  
Uma Gabale ◽  
Perla A. Peña Palomino ◽  
HyunAh Kim ◽  
Wenya Chen ◽  
Susanne Ressl
Keyword(s):  
Antibiotic Resistance ◽  
Membrane Protein ◽  
Outer Membrane ◽  
Essential Gene ◽  
Critical Role ◽  
Gram Negative Bacteria ◽  
Inner Membrane ◽  
Gram Negative ◽  
Periplasmic Domain ◽  
Inner Membrane Protein

AbstractRecent 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 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 by translocating and increasing the cardiolipin lipid concentration. How the inner membrane protein YejM with its periplasmic domain acts as a cardiolipin translocator remains unknown. Despite overwhelming structural similarity of the periplasmic domains of two YejM homologues with hydrolases like arylsulfatases, no enzymatic activity has been 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 cardiolipin translocation properties. Understanding the molecular mechanism by which YejM is involved in OM remodeling will help to identify a new drug target in the fight against the increased antibiotic resistance.

scholarly journals Genetic analysis of the role of the conserved inner membrane protein CvpA in EHEC resistance to deoxycholate

2020 ◽  
Author(s):  
Alyson R. Warr ◽  
Rachel T. Giorgio ◽  
Matthew K. Waldor
Keyword(s):  
Stress Response ◽  
Membrane Protein ◽  
Bile Salt ◽  
Cell Envelope ◽  
Enteric Bacteria ◽  
Enteric Pathogens ◽  
Inner Membrane ◽  
Bacterial Phyla ◽  
E Coli ◽  
Inner Membrane Protein

The function of cvpA, a bacterial gene predicted to encode an inner membrane protein, is largely unknown. Early studies in E. coli linked cvpA to Colicin V secretion and recent work revealed that it is required for robust intestinal colonization by diverse enteric pathogens. In enterohemorrhagic E. coli (EHEC), cvpA is required for resistance to the bile salt deoxycholate (DOC). Here, we carried out genome-scale transposon-insertion mutagenesis and spontaneous suppressor analysis to uncover cvpA’s genetic interactions and identify common pathways that rescue the sensitivity of a ΔcvpA EHEC mutant to DOC. These screens demonstrated that mutations predicted to activate the σE-mediated extracytoplasmic stress response bypass the ΔcvpA mutant’s susceptibility to DOC. Consistent with this idea, we found that deletions in rseA and msbB and direct overexpression of rpoE restored DOC resistance to the ΔcvpA mutant. Analysis of the distribution of CvpA homologs revealed that this inner membrane protein is conserved across diverse bacterial phyla, in both enteric and non-enteric bacteria that are not exposed to bile. Together, our findings suggest that CvpA plays a role in cell envelope homeostasis in response to DOC and similar stress stimuli in diverse bacterial species. IMPORTANCE Several enteric pathogens, including Enterohemorrhagic E. coli (EHEC), require CvpA to robustly colonize the intestine. This inner membrane protein is also important for secretion of a colicin and EHEC resistance to the bile salt deoxycholate (DOC), but its function is unknown. Genetic analyses carried out here showed that activation of the σE-mediated extracytoplasmic stress response restored the resistance of a cvpA mutant to DOC, suggesting that CvpA plays a role in cell envelope homeostasis. The conservation of CvpA across diverse bacterial phyla suggests that this membrane protein facilitates cell envelope homeostasis in response to varied cell envelope perturbations.

scholarly journals YieJ (CbrC) Mediates CreBC-Dependent Colicin E2 Tolerance in Escherichia coli

2010 ◽  
Vol 192 (13) ◽  
pp. 3329-3336 ◽  
Author(s):  
S. James L. Cariss ◽  
Chrystala Constantinidou ◽  
Mala D. Patel ◽  
Yuiko Takebayashi ◽  
Jon L. Hobman ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Membrane Protein ◽  
Microarray Analysis ◽  
Gene Knockout ◽  
Inner Membrane ◽  
Two Component ◽  
Inner Membrane Protein ◽  
Colicin E2 ◽  
K 12

ABSTRACT Colicin E2-tolerant (known as Cet2) Escherichia coli K-12 mutants overproduce an inner membrane protein, CreD, which is believed to cause the Cet2 phenotype. Here, we show that overproduction of CreD in a Cet2 strain results from hyperactivation of the CreBC two-component regulator, but CreD overproduction is not responsible for the Cet2 phenotype. Through microarray analysis and gene knockout and overexpression studies, we show that overexpression of another CreBC-regulated gene, yieJ (also known as cbrC), causes the Cet2 phenotype.

scholarly journals Characterization of the two conformations adopted by the T3SS inner-membrane protein PrgK

2018 ◽  
Vol 27 (9) ◽  
pp. 1680-1691
Author(s):  
Julien R. C. Bergeron ◽  
Jacob A. Brockerman ◽  
Marija Vuckovic ◽  
Wanyin Deng ◽  
Mark Okon ◽  
...  
Keyword(s):  
Membrane Protein ◽  
Inner Membrane ◽  
Inner Membrane Protein
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