Structural Basis of Peptide-Based Antimicrobial Inhibition of a Resistance-Nodulation-Cell Division Multidrug Efflux Pump
ABSTRACT Bacterial efflux pumps in the resistance-nodulation-cell division (RND) family of Gram-negative bacteria contribute significantly to the development of antimicrobial resistance by many pathogens. In this study, we selected the MtrD transporter protein of Neisseria gonorrhoeae as it is the s...
| Main Authors: | , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
American Society for Microbiology
2022-10-01
|
| Series: | Microbiology Spectrum |
| Subjects: | |
| Online Access: | https://journals.asm.org/doi/10.1128/spectrum.02990-22 |
| _version_ | 1811198187897094144 |
|---|---|
| author | Meinan Lyu Julio C. Ayala Isabella Chirakos Chih-Chia Su William M. Shafer Edward W. Yu |
| author_facet | Meinan Lyu Julio C. Ayala Isabella Chirakos Chih-Chia Su William M. Shafer Edward W. Yu |
| author_sort | Meinan Lyu |
| collection | DOAJ |
| description | ABSTRACT Bacterial efflux pumps in the resistance-nodulation-cell division (RND) family of Gram-negative bacteria contribute significantly to the development of antimicrobial resistance by many pathogens. In this study, we selected the MtrD transporter protein of Neisseria gonorrhoeae as it is the sole RND pump possessed by this strictly human pathogen and can export multiple antimicrobials, including antibiotics, bile salts, detergents, dyes, and antimicrobial peptides. Using knowledge from our previously published structures of MtrD in the presence or absence of bound antibiotics as a model and the known ability of MtrCDE to export cationic antimicrobial peptides, we hypothesized that cationic peptides could be accommodated within MtrD binding sites. Furthermore, we thought that MtrD-bound peptides lacking antibacterial action could sensitize bacteria to an antibiotic normally exported by the MtrCDE efflux pump or other similar RND-type pumps possessed by different Gram-negative bacteria. We now report the identification of a novel nonantimicrobial cyclic cationic antimicrobial peptide, which we termed CASP (cationic antibiotic-sensitizing peptide). By single-particle cryo-electron microscopy, we found that CASP binds within the periplasmic cleft region of MtrD using overlapping and distinct amino acid contact sites that interact with another cyclic peptide (colistin) or a linear human cationic antimicrobial peptide derived from human LL-37. While CASP could not sensitize Neisseria gonorrhoeae to an antibiotic (novobiocin) that is a substrate for RND pumps, it could do so against multiple Gram-negative, rod-shaped bacteria. We propose that CASP (or future derivatives) could serve as an adjuvant for the antibiotic treatment of certain Gram-negative infections previously thwarted by RND transporters. IMPORTANCE RND efflux pumps can export numerous antimicrobials that enter Gram-negative bacteria, and their action can reduce the efficacy of antibiotics and provide decreased susceptibility to various host antimicrobials. Here, we identified a cationic antibiotic-sensitizing peptide (CASP) that binds within the periplasmic cleft of an RND transporter protein (MtrD) produced by Neisseria gonorrhoeae. Surprisingly, CASP was able to render rod-shaped Gram-negative bacteria, but not gonococci, susceptible to an antibiotic that is a substrate for the gonococcal MtrCDE efflux pump. CASP (or its future derivatives) could be used as an adjuvant to treat infections for which RND efflux contributes to multidrug resistance. |
| first_indexed | 2024-04-12T01:26:33Z |
| format | Article |
| id | doaj.art-b761035e831d443f9afe462b16670731 |
| institution | Directory Open Access Journal |
| issn | 2165-0497 |
| language | English |
| last_indexed | 2024-04-12T01:26:33Z |
| publishDate | 2022-10-01 |
| publisher | American Society for Microbiology |
| record_format | Article |
| series | Microbiology Spectrum |
| spelling | doaj.art-b761035e831d443f9afe462b166707312022-12-22T03:53:38ZengAmerican Society for MicrobiologyMicrobiology Spectrum2165-04972022-10-0110510.1128/spectrum.02990-22Structural Basis of Peptide-Based Antimicrobial Inhibition of a Resistance-Nodulation-Cell Division Multidrug Efflux PumpMeinan Lyu0Julio C. Ayala1Isabella Chirakos2Chih-Chia Su3William M. Shafer4Edward W. Yu5Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, Ohio, USADepartment of Microbiology and Immunology, Emory University School of Medicine, Atlanta, Georgia, USADepartment of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, Ohio, USADepartment of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, Ohio, USADepartment of Microbiology and Immunology, Emory University School of Medicine, Atlanta, Georgia, USADepartment of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, Ohio, USAABSTRACT Bacterial efflux pumps in the resistance-nodulation-cell division (RND) family of Gram-negative bacteria contribute significantly to the development of antimicrobial resistance by many pathogens. In this study, we selected the MtrD transporter protein of Neisseria gonorrhoeae as it is the sole RND pump possessed by this strictly human pathogen and can export multiple antimicrobials, including antibiotics, bile salts, detergents, dyes, and antimicrobial peptides. Using knowledge from our previously published structures of MtrD in the presence or absence of bound antibiotics as a model and the known ability of MtrCDE to export cationic antimicrobial peptides, we hypothesized that cationic peptides could be accommodated within MtrD binding sites. Furthermore, we thought that MtrD-bound peptides lacking antibacterial action could sensitize bacteria to an antibiotic normally exported by the MtrCDE efflux pump or other similar RND-type pumps possessed by different Gram-negative bacteria. We now report the identification of a novel nonantimicrobial cyclic cationic antimicrobial peptide, which we termed CASP (cationic antibiotic-sensitizing peptide). By single-particle cryo-electron microscopy, we found that CASP binds within the periplasmic cleft region of MtrD using overlapping and distinct amino acid contact sites that interact with another cyclic peptide (colistin) or a linear human cationic antimicrobial peptide derived from human LL-37. While CASP could not sensitize Neisseria gonorrhoeae to an antibiotic (novobiocin) that is a substrate for RND pumps, it could do so against multiple Gram-negative, rod-shaped bacteria. We propose that CASP (or future derivatives) could serve as an adjuvant for the antibiotic treatment of certain Gram-negative infections previously thwarted by RND transporters. IMPORTANCE RND efflux pumps can export numerous antimicrobials that enter Gram-negative bacteria, and their action can reduce the efficacy of antibiotics and provide decreased susceptibility to various host antimicrobials. Here, we identified a cationic antibiotic-sensitizing peptide (CASP) that binds within the periplasmic cleft of an RND transporter protein (MtrD) produced by Neisseria gonorrhoeae. Surprisingly, CASP was able to render rod-shaped Gram-negative bacteria, but not gonococci, susceptible to an antibiotic that is a substrate for the gonococcal MtrCDE efflux pump. CASP (or its future derivatives) could be used as an adjuvant to treat infections for which RND efflux contributes to multidrug resistance.https://journals.asm.org/doi/10.1128/spectrum.02990-22MtrDNeisseria gonorrhoeaemembrane proteinsmultidrug effluxmultidrug resistancesecondary transporter mechanism |
| spellingShingle | Meinan Lyu Julio C. Ayala Isabella Chirakos Chih-Chia Su William M. Shafer Edward W. Yu Structural Basis of Peptide-Based Antimicrobial Inhibition of a Resistance-Nodulation-Cell Division Multidrug Efflux Pump Microbiology Spectrum MtrD Neisseria gonorrhoeae membrane proteins multidrug efflux multidrug resistance secondary transporter mechanism |
| title | Structural Basis of Peptide-Based Antimicrobial Inhibition of a Resistance-Nodulation-Cell Division Multidrug Efflux Pump |
| title_full | Structural Basis of Peptide-Based Antimicrobial Inhibition of a Resistance-Nodulation-Cell Division Multidrug Efflux Pump |
| title_fullStr | Structural Basis of Peptide-Based Antimicrobial Inhibition of a Resistance-Nodulation-Cell Division Multidrug Efflux Pump |
| title_full_unstemmed | Structural Basis of Peptide-Based Antimicrobial Inhibition of a Resistance-Nodulation-Cell Division Multidrug Efflux Pump |
| title_short | Structural Basis of Peptide-Based Antimicrobial Inhibition of a Resistance-Nodulation-Cell Division Multidrug Efflux Pump |
| title_sort | structural basis of peptide based antimicrobial inhibition of a resistance nodulation cell division multidrug efflux pump |
| topic | MtrD Neisseria gonorrhoeae membrane proteins multidrug efflux multidrug resistance secondary transporter mechanism |
| url | https://journals.asm.org/doi/10.1128/spectrum.02990-22 |
| work_keys_str_mv | AT meinanlyu structuralbasisofpeptidebasedantimicrobialinhibitionofaresistancenodulationcelldivisionmultidrugeffluxpump AT juliocayala structuralbasisofpeptidebasedantimicrobialinhibitionofaresistancenodulationcelldivisionmultidrugeffluxpump AT isabellachirakos structuralbasisofpeptidebasedantimicrobialinhibitionofaresistancenodulationcelldivisionmultidrugeffluxpump AT chihchiasu structuralbasisofpeptidebasedantimicrobialinhibitionofaresistancenodulationcelldivisionmultidrugeffluxpump AT williammshafer structuralbasisofpeptidebasedantimicrobialinhibitionofaresistancenodulationcelldivisionmultidrugeffluxpump AT edwardwyu structuralbasisofpeptidebasedantimicrobialinhibitionofaresistancenodulationcelldivisionmultidrugeffluxpump |