scholarly journals Molecular cloning and characterization of SmrA, a novel ABC multidrug efflux pump from Stenotrophomonas maltophilia

2009 ◽  
Vol 64 (4) ◽  
pp. 731-734 ◽  
Author(s):  
A. Al-Hamad ◽  
M. Upton ◽  
J. Burnie
Keyword(s):  
Molecular Cloning ◽  
Stenotrophomonas Maltophilia ◽  
Efflux Pump ◽  
Multidrug Efflux ◽  
Multidrug Efflux Pump

scholarly journals Cloning and Characterization of SmeT, a Repressor of the Stenotrophomonas maltophilia Multidrug Efflux Pump SmeDEF

2002 ◽  
Vol 46 (11) ◽  
pp. 3386-3393 ◽  
Author(s):  
Patricia Sánchez ◽  
Ana Alonso ◽  
Jose L. Martinez
Keyword(s):  
Stenotrophomonas Maltophilia ◽  
Efflux Pump ◽  
Wild Type ◽  
Multidrug Efflux ◽  
Multidrug Efflux Pump ◽  
S1 Nuclease ◽  
Cellular Factor ◽  
S1 Nuclease Mapping ◽  
Nuclease Mapping

ABSTRACT We report on the cloning of the gene smeT, which encodes the transcriptional regulator of the Stenotrophomonas maltophilia efflux pump SmeDEF. SmeT belongs to the TetR and AcrR family of transcriptional regulators. The smeT gene is located upstream from the structural operon of the pump genes smeDEF and is divergently transcribed from those genes. Experiments with S. maltophilia and the heterologous host Escherichia coli have demonstrated that SmeT is a transcriptional repressor. S1 nuclease mapping has demonstrated that expression of smeT is driven by a single promoter lying close to the 5′ end of the gene and that expression of smeDEF is driven by an unique promoter that overlaps with promoter PsmeT. The level of expression of smeT is higher in smeDEF-overproducing S. maltophilia strain D457R, which suggests that SmeT represses its own expression. Band-shifting assays have shown that wild-type strain S. maltophilia D457 contains a cellular factor(s) capable of binding to the intergenic smeT-smeD region. That cellular factor(s) was absent from smeDEF-overproducing S. maltophilia strain D457R. The sequence of smeT from D457R showed a point mutation that led to a Leu166Gln change within the SmeT protein. This change allowed overexpression of both smeDEF and smeT in D457R. It was noteworthy that expression of wild-type SmeT did not fully complement the smeT mutation in D457R. This suggests that the wild-type protein is not dominant over the mutant SmeT.

scholarly journals Molecular Cloning and Characterization of the HmrM Multidrug Efflux Pump fromHaemophilus influenzaeRd

2003 ◽  
Vol 47 (12) ◽  
pp. 937-943 ◽  
Author(s):  
Xing-Jue Xu ◽  
Xian-Zhong Su ◽  
Yuji Morita ◽  
Teruo Kuroda ◽  
Tohru Mizushima ◽  
...  
Keyword(s):  
Molecular Cloning ◽  
Efflux Pump ◽  
Multidrug Efflux ◽  
Multidrug Efflux Pump

scholarly journals Molecular Cloning and Characterization of a Multidrug Efflux Pump, SmfY, from Serratia marcescens

2007 ◽  
Vol 30 (4) ◽  
pp. 798-800 ◽  
Author(s):  
Fereshteh Shahcheraghi ◽  
Yusuke Minato ◽  
Jing Chen ◽  
Tohru Mizushima ◽  
Wakano Ogawa ◽  
...  
Keyword(s):  
Serratia Marcescens ◽  
Molecular Cloning ◽  
Efflux Pump ◽  
Multidrug Efflux ◽  
Multidrug Efflux Pump

scholarly journals Gene Cloning and Characterization of VcrM, a Na+-Coupled Multidrug Efflux Pump, fromVibrio choleraeNon-O1

2003 ◽  
Vol 47 (6) ◽  
pp. 419-427 ◽  
Author(s):  
Md. Nazmul Huda ◽  
Jing Chen ◽  
Yuji Morita ◽  
Teruo Kuroda ◽  
Tohru Mizushima ◽  
...  
Keyword(s):  
Gene Cloning ◽  
Efflux Pump ◽  
Multidrug Efflux ◽  
Multidrug Efflux Pump ◽  
Gene Cloning And Characterization

Characterization of the Serratia marcescens SdeCDE multidrug efflux pump studied via gene knockout mutagenesis

2008 ◽  
Vol 54 (5) ◽  
pp. 411-416 ◽  
Author(s):  
Sanela Begic ◽  
Elizabeth A. Worobec
Keyword(s):  
Antibiotic Resistance ◽  
Substrate Specificity ◽  
Serratia Marcescens ◽  
Efflux Pump ◽  
Gene Knockout ◽  
Multidrug Efflux ◽  
Multidrug Efflux Pump ◽  
Active Efflux ◽  
Major Mechanism

Serratia marcescens is an important nosocomial agent having high antibiotic resistance. A major mechanism for S. marcescens antibiotic resistance is active efflux. To ascertain the substrate specificity of the S. marcescens SdeCDE efflux pump, we constructed pump gene deletion mutants. sdeCDE knockout strains showed no change in antibiotic susceptibility in comparison with the parental strains for any of the substrates, with the exception of novobiocin. In addition, novobiocin was the only antibiotic to be accumulated by sdeCDE-deficient strains. Based on the substrates used in our study, we conclude that SdeCDE is a Resistance–Nodulation–Cell Division family pump with limited substrate specificity.

scholarly journals Functional Cloning and Characterization of a Multidrug Efflux Pump, MexHI-OpmD, from a Pseudomonas aeruginosa Mutant

2003 ◽  
Vol 47 (9) ◽  
pp. 2990-2992 ◽  
Author(s):  
Hiroshi Sekiya ◽  
Takehiko Mima ◽  
Yuji Morita ◽  
Teruo Kuroda ◽  
Tohru Mizushima ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Ethidium Bromide ◽  
Rhodamine 6G ◽  
Efflux Pump ◽  
Efflux Pumps ◽  
Multidrug Efflux ◽  
Chromosomal Dna ◽  
Multidrug Efflux Pump ◽  
Multidrug Efflux Pumps

ABSTRACT We isolated mutant YM644, which showed elevated resistance to norfloxacin, ethidium bromide, acriflavine, and rhodamine 6G, from Pseudomonas aeruginosa YM64, a strain that lacks four major multidrug efflux pumps. The genes responsible for the resistance were mexHI-opmD. Elevated ethidium extrusion was observed with cells of YM644 and YM64 harboring a plasmid carrying the genes. Disruption of the genes in the chromosomal DNA of YM644 made the cells sensitive to the drugs.

scholarly journals Structural, Biochemical, and In Vivo Characterization of MtrR-Mediated Resistance to Innate Antimicrobials by the Human Pathogen Neisseria gonorrhoeae

2019 ◽  
Vol 201 (20) ◽  
Author(s):  
Grace A. Beggs ◽  
Yaramah M. Zalucki ◽  
Nicholas Gene Brown ◽  
Sheila Rastegari ◽  
Rebecca K. Phillips ◽  
...  
Keyword(s):  
Neisseria Gonorrhoeae ◽  
Bile Salts ◽  
Efflux Pump ◽  
Binding Modes ◽  
Multidrug Efflux ◽  
Multidrug Efflux Pump ◽  
Content Type ◽  
Multiple Drugs

ABSTRACT Neisseria gonorrhoeae responds to host-derived antimicrobials by inducing the expression of the mtrCDE-encoded multidrug efflux pump, which expels microbicides, such as bile salts, fatty acids, and multiple extrinsically administered drugs, from the cell. In the absence of these cytotoxins, the TetR family member MtrR represses the mtrCDE genes. Although antimicrobial-dependent derepression of mtrCDE is clear, the physiological inducers of MtrR are unknown. Here, we report the crystal structure of an induced form of MtrR. In the binding pocket of MtrR, we observed electron density that we hypothesized was N-cyclohexyl-3-aminopropanesulfonic acid (CAPS), a component of the crystallization reagent. Using the MtrR-CAPS structure as an inducer-bound template, we hypothesized that bile salts, which bear significant chemical resemblance to CAPS, are physiologically relevant inducers. Indeed, characterization of MtrR-chenodeoxycholate and MtrR-taurodeoxycholate interactions, both in vitro and in vivo, revealed that these bile salts, but not glyocholate or taurocholate, bind MtrR tightly and can act as bona fide inducers. Furthermore, two residues, W136 and R176, were shown to be important in binding chenodeoxycholate but not taurodeoxycholate, suggesting different binding modes of the bile salts. These data provide insight into a crucial mechanism utilized by the pathogen to overcome innate human defenses. IMPORTANCE Neisseria gonorrhoeae causes a significant disease burden worldwide, and a meteoric rise in its multidrug resistance has reduced the efficacy of antibiotics previously or currently approved for therapy of gonorrheal infections. The multidrug efflux pump MtrCDE transports multiple drugs and host-derived antimicrobials from the bacterial cell and confers survival advantage on the pathogen within the host. Transcription of the pump is repressed by MtrR but relieved by the cytosolic influx of antimicrobials. Here, we describe the structure of induced MtrR and use this structure to identify bile salts as physiological inducers of MtrR. These findings provide a mechanistic basis for antimicrobial sensing and gonococcal protection by MtrR through the derepression of mtrCDE expression after exposure to intrinsic and clinically applied antimicrobials.

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