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Sabotič J, Janež N, Volk M, Klančnik A. Molecular structures mediating adhesion of Campylobacter jejuni to abiotic and biotic surfaces. Vet Microbiol 2023; 287:109918. [PMID: 38029692 DOI: 10.1016/j.vetmic.2023.109918] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 11/13/2023] [Accepted: 11/19/2023] [Indexed: 12/01/2023]
Abstract
Microaerophilic, Gram-negative Campylobacter jejuni is the causative agent of campylobacteriosis, the most common bacterial gastrointestinal infection worldwide. Adhesion is the crucial first step in both infection or interaction with the host and biofilm formation, and is a critical factor for bacterial persistence. Here we describe the proteins and other surface structures that promote adhesion to various surfaces, including abiotic surfaces, microorganisms, and animal and human hosts. In addition, we provide insight into the distribution of adhesion proteins among strains from different ecological niches and highlight unexplored proteins involved in C. jejuni adhesion. Protein-protein, protein-glycan, and glycan-glycan interactions are involved in C. jejuni adhesion, with different factors contributing to adhesion to varying degrees under different circumstances. As adhesion is essential for survival and persistence, it represents an interesting target for C. jejuni control. Knowledge of the adhesion process is incomplete, as different molecular and functional aspects have been studied for different structures involved in adhesion. Therefore, it is important to strive for an integration of different approaches to obtain a clearer picture of the adhesion process on different surfaces and to consider the involvement of proteins, glycoconjugates, and polysaccharides and their cooperation.
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Affiliation(s)
- Jerica Sabotič
- Department of Biotechnology, Jožef Stefan Institute, Ljubljana, Slovenia
| | - Nika Janež
- Department of Biotechnology, Jožef Stefan Institute, Ljubljana, Slovenia
| | - Manca Volk
- Department of Food Science and Technology, Biotechnical Faculty, University of Ljubljana, Slovenia
| | - Anja Klančnik
- Department of Food Science and Technology, Biotechnical Faculty, University of Ljubljana, Slovenia.
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Functional Genomics Identified Novel Genes Involved in Growth at Low Temperatures in Listeria monocytogenes. Microbiol Spectr 2022; 10:e0071022. [PMID: 35735974 PMCID: PMC9431668 DOI: 10.1128/spectrum.00710-22] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Listeria monocytogenes (Lm) is a foodborne pathogen that can cause severe human illness. Standard control measures for restricting bacterial growth, such as refrigeration, are often inadequate as Lm grows well at low temperatures. To identify genes involved in growth at low temperatures, a powerful functional genomics method Tn-seq was performed in this study. This genome-wide screening comprehensively identified the known and novel genetic determinants involved in low-temperature growth. A novel gene lmo1366, encoding rRNA methyltransferase, was identified to play an essential role in Lm growth at 16°C. In contrast, the inactivation of lmo2301, a gene encoding the terminase of phage A118, significantly enhanced the growth of Lm at 16°C. The deletion of lmo1366 or lmo2301 resulted in cell morphology alterations and impaired the growth rate in milk and other conditions at low temperatures. Transcriptomic analysis revealed that the Δlmo1366 and Δlmo2301 mutants exhibited altered transcriptional patterns compared to the wild-type strain at 16°C with significant differences in genes involved in ribosome structural stability and function, and membrane biogenesis, respectively. This work uncovered novel genetic determinants involved in Lm growth at 16°C, which could lead to a better understanding of how bacteria survive and multiply at low temperatures. Furthermore, these findings could potentially contribute to developing novel antibacterial strategies under low-temperature conditions. IMPORTANCEListeria monocytogenes is a Gram-positive pathogen that contributes to foodborne outbreaks due to its ability to survive at low temperatures. However, the genetic determinants of Lm involved in growth at low temperatures have not been fully defined. Here, the genetic determinants involved in the low-temperature growth of Lm were comprehensively identified on a genome-wide scale by Tn-seq. The gene lmo1366, encoding rRNA methyltransferase, was identified essential for growth under low-temperature conditions. On the other hand, the gene lmo2301, encoding terminase of phage A118, plays a negative role in bacterial growth at low temperatures. The transcriptomic analysis revealed the potential mechanisms. These findings lead to a better understanding of how bacteria survive and multiply at low temperatures and could provide unique targets for novel antibacterial strategies under low-temperature conditions.
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Laughlin ZT, Nandi S, Dey D, Zelinskaya N, Witek MA, Srinivas P, Nguyen HA, Kuiper EG, Comstock LR, Dunham CM, Conn GL. 50S subunit recognition and modification by the Mycobacterium tuberculosis ribosomal RNA methyltransferase TlyA. Proc Natl Acad Sci U S A 2022; 119:e2120352119. [PMID: 35357969 PMCID: PMC9168844 DOI: 10.1073/pnas.2120352119] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Accepted: 02/22/2022] [Indexed: 11/18/2022] Open
Abstract
Changes in bacterial ribosomal RNA (rRNA) methylation status can alter the activity of diverse groups of ribosome-targeting antibiotics. These modifications are typically incorporated by a single methyltransferase that acts on one nucleotide target and rRNA methylation directly prevents drug binding, thereby conferring drug resistance. Loss of intrinsic methylation can also result in antibiotic resistance. For example, Mycobacterium tuberculosis becomes sensitized to tuberactinomycin antibiotics, such as capreomycin and viomycin, due to the action of the intrinsic methyltransferase TlyA. TlyA is unique among antibiotic resistance-associated methyltransferases as it has dual 16S and 23S rRNA substrate specificity and can incorporate cytidine-2′-O-methylations within two structurally distinct contexts. Here, we report the structure of a mycobacterial 50S subunit-TlyA complex trapped in a postcatalytic state with a S-adenosyl-L-methionine analog using single-particle cryogenic electron microscopy. Together with complementary functional analyses, this structure reveals critical roles in 23S rRNA substrate recognition for conserved residues across an interaction surface that spans both TlyA domains. These interactions position the TlyA active site over the target nucleotide C2144, which is flipped from 23S Helix 69 in a process stabilized by stacking of TlyA residue Phe157 on the adjacent A2143. Base flipping may thus be a common strategy among rRNA methyltransferase enzymes, even in cases where the target site is accessible without such structural reorganization. Finally, functional studies with 30S subunit suggest that the same TlyA interaction surface is employed to recognize this second substrate, but with distinct dependencies on essential conserved residues.
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Affiliation(s)
- Zane T. Laughlin
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322
- Graduate Program in Biochemistry, Cell and Developmental Biology, Graduate Division of Biological and Biomedical Sciences, Emory University, Atlanta, GA 30322
| | - Suparno Nandi
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322
| | - Debayan Dey
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322
| | - Natalia Zelinskaya
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322
| | - Marta A. Witek
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322
| | - Pooja Srinivas
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322
- Graduate Program in Molecular and Systems Pharmacology, Graduate Division of Biological and Biomedical Sciences, Emory University, Atlanta, GA 30322
| | - Ha An Nguyen
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322
- Department of Chemistry Graduate Program, Emory University, Atlanta, GA 30322
| | - Emily G. Kuiper
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322
| | | | - Christine M. Dunham
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322
- Emory Antibiotic Resistance Center, Emory University, Atlanta, GA 30322
| | - Graeme L. Conn
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322
- Emory Antibiotic Resistance Center, Emory University, Atlanta, GA 30322
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Keith BA, Harding JCS, Loewen ME. Mutational analysis of TlyA from Brachyspira hampsonii reveals two key residues conserved in pathogenic bacteria responsible for oligomerization and hemolytic activity. Biochim Biophys Acta Gen Subj 2022; 1866:130045. [PMID: 34715264 DOI: 10.1016/j.bbagen.2021.130045] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 10/07/2021] [Accepted: 10/22/2021] [Indexed: 12/01/2022]
Abstract
BACKGROUND TlyA proteins are expressed in a variety of pathogenic bacteria and possess dual hemolytic and ribosomal RNA methyltransferase functions. While the mechanism of TlyA mediated rRNA methylation is well understood, relatively little is known about the mechanism of TlyA induced hemolysis. METHODS TlyA protein from the pig pathogen Brachyspira hampsonii was heterologously expressed and purified from an E. coli host. Hemolytic activity and rRNA methylation were assessed in vitro. Site-directed mutagenesis was used to mutate amino acids believed to be involved in TlyA mediated hemolysis. RESULTS Purified TlyA-His protein exhibited both hemolytic and rRNA methyltransferase activities in vitro, with partial inhibition of hemolysis observed under reducing conditions. Mutation of cysteine 80 to alanine impaired hemolytic activity. A C27A/C93A mutant was capable of dimerizing under non-reducing conditions, indicating that a C80-C80 disulfide bond is involved in TlyA oligomerization. A mutation conserved in several avirulent Brachyspira species (S9K) completely abolished hemolytic activity of TlyA. This loss of activity was attributed to impaired oligomerization in the S9K mutant, as assessed by ITC and size-exclusion chromatography experiments. CONCLUSIONS Oligomeric assembly and hemolytic activity of TlyA from Brachyspira hampsonii is dependent on the formation of an intermolecular C80-C80 disulfide bond and noncovalent interactions involving serine 9. The conservation of these amino acids in TlyA proteins from pathogenic bacteria suggests a correlation between tlyA gene mutations and bacterial virulence. GENERAL SIGNIFICANCE Our results further elucidate the mechanisms underlying TlyA mediated hemolysis and provide evidence of a conserved mechanism of oligomerization for TlyA family proteins.
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Affiliation(s)
- Brandon A Keith
- Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Canada
| | - John C S Harding
- Department of Large Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Canada
| | - Matthew E Loewen
- Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Canada.
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Laughlin ZT, Conn GL. Tuberactinomycin antibiotics: Biosynthesis, anti-mycobacterial action, and mechanisms of resistance. Front Microbiol 2022; 13:961921. [PMID: 36033858 PMCID: PMC9403184 DOI: 10.3389/fmicb.2022.961921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2022] [Accepted: 07/21/2022] [Indexed: 12/04/2022] Open
Abstract
The tuberactinomycins are a family of cyclic peptide ribosome-targeting antibiotics with a long history of use as essential second-line treatments for drug-resistant tuberculosis. Beginning with the identification of viomycin in the early 1950s, this mini-review briefly describes tuberactinomycin structures and biosynthesis, as well as their past and present application in the treatment of tuberculosis caused by infection with Mycobacterium tuberculosis. More recent studies are also discussed that have revealed details of tuberactinomycin action on the ribosome as well as resistance mechanisms that have emerged since their introduction into the clinic. Finally, future applications of these drugs are considered in the context of their recent removal from the World Health Organization's List of Essential Medicines.
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Affiliation(s)
- Zane T Laughlin
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, United States.,Graduate Program in Biochemistry, Cell and Developmental Biology (BCDB), Graduate Division of Biological and Biomedical Sciences, Emory University, Atlanta, GA, United States
| | - Graeme L Conn
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, United States.,Emory Antibiotic Resistance Center (ARC), Emory University, Atlanta, GA, United States
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Sałamaszyńska-Guz A, Serafińska I, Bącal P, Douthwaite S. Virulence properties of Campylobacter jejuni are enhanced by displaying a mycobacterial TlyA methylation pattern in its rRNA. Cell Microbiol 2020; 22:e13199. [PMID: 32134554 PMCID: PMC7317525 DOI: 10.1111/cmi.13199] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 01/24/2020] [Accepted: 02/23/2020] [Indexed: 01/18/2023]
Abstract
Campylobacter jejuni is a bacterial pathogen that is generally acquired as a zoonotic infection from poultry and animals. Adhesion of C. jejuni to human colorectal epithelial cells is weakened after loss of its cj0588 gene. The Cj0588 protein belongs to the type I group of TlyA (TlyAI) enzymes, which 2′‐O‐methylate nucleotide C1920 in 23S rRNA. Slightly longer TlyAII versions of the methyltransferase are found in actinobacterial species including Mycobacterium tuberculosis, and methylate not only C1920 but also nucleotide C1409 in 16S rRNA. Loss of TlyA function attenuates virulence of both M. tuberculosis and C. jejuni. We show here that the traits impaired in C. jejuni null strains can be rescued by complementation not only with the original cj0588 (tlyAI) but also with a mycobacterial tlyAII gene. There are, however, significant differences in the recombinant phenotypes. While cj0588 restores motility, biofilm formation, adhesion to and invasion of human epithelial cells and stimulation of IL‐8 production in a C. jejuni null strain, several of these properties are further enhanced by the mycobacterial tlyAII gene, in some cases to twice the original wild‐type level. These findings strongly suggest that subtle changes in rRNA modification patterns can affect protein synthesis in a manner that has serious consequences for bacterial pathogenicity.
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Affiliation(s)
- Agnieszka Sałamaszyńska-Guz
- Division of Microbiology, Department of Pre-Clinical Sciences, Institute of Veterinary Medicine, Warsaw University of Live Sciences - SGGW, Warsaw, Poland
| | - Izabela Serafińska
- Division of Microbiology, Department of Pre-Clinical Sciences, Institute of Veterinary Medicine, Warsaw University of Live Sciences - SGGW, Warsaw, Poland
| | - Paweł Bącal
- Laboratory of Theory and Applications of Electrodes, Faculty of Chemistry, University of Warsaw, Warsaw, Poland.,Nałęcz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Warsaw, Poland
| | - Stephen Douthwaite
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense M, Denmark
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Sałamaszyńska-Guz A, Rose S, Lykkebo CA, Taciak B, Bącal P, Uśpieński T, Douthwaite S. Biofilm Formation and Motility Are Promoted by Cj0588-Directed Methylation of rRNA in Campylobacter jejuni. Front Cell Infect Microbiol 2018; 7:533. [PMID: 29404277 PMCID: PMC5778110 DOI: 10.3389/fcimb.2017.00533] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Accepted: 12/20/2017] [Indexed: 12/25/2022] Open
Abstract
Numerous bacterial pathogens express an ortholog of the enzyme TlyA, which is an rRNA 2′-O-methyltransferase associated with resistance to cyclic peptide antibiotics such as capreomycin. Several other virulence traits have also been attributed to TlyA, and these appear to be unrelated to its methyltransferase activity. The bacterial pathogen Campylobacter jejuni possesses the TlyA homolog Cj0588, which has been shown to contribute to virulence. Here, we investigate the mechanism of Cj0588 action and demonstrate that it is a type I homolog of TlyA that 2′-O-methylates 23S rRNA nucleotide C1920. This same specific function is retained by Cj0588 both in vitro and also when expressed in Escherichia coli. Deletion of the cj0588 gene in C. jejuni or substitution with alanine of K80, D162, or K188 in the catalytic center of the enzyme cause complete loss of 2′-O-methylation activity. Cofactor interactions remain unchanged and binding affinity to the ribosomal substrate is only slightly reduced, indicating that the inactivated proteins are folded correctly. The substitution mutations thus dissociate the 2′-O-methylation function of Cj0588/TlyA from any other putative roles that the protein might play. C. jejuni strains expressing catalytically inactive versions of Cj0588 have the same phenotype as cj0588-null mutants, and show altered tolerance to capreomycin due to perturbed ribosomal subunit association, reduced motility and impaired ability to form biofilms. These functions are reestablished when methyltransferase activity is restored and we conclude that the contribution of Cj0588 to virulence in C. jejuni is a consequence of the enzyme's ability to methylate its rRNA.
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Affiliation(s)
- Agnieszka Sałamaszyńska-Guz
- Division of Microbiology, Department of Pre-Clinical Sciences, Faculty of Veterinary Medicine, Warsaw University of Life Sciences, Warsaw, Poland
| | - Simon Rose
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | - Claus A Lykkebo
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | - Bartłomiej Taciak
- Division of Physiology, Department of Physiological Sciences, Faculty of Veterinary Medicine, Warsaw University of Life Sciences, Warsaw, Poland
| | - Paweł Bącal
- Laboratory of Theory and Applications of Electrodes, Faculty of Chemistry, University of Warsaw, Warsaw, Poland
| | - Tomasz Uśpieński
- Division of Microbiology, Department of Pre-Clinical Sciences, Faculty of Veterinary Medicine, Warsaw University of Life Sciences, Warsaw, Poland
| | - Stephen Douthwaite
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
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Javadi MB, Katzenmeier G. The Forgotten Virulence Factor: The 'non-conventional' Hemolysin TlyA And Its Role in Helicobacter pylori Infection. Curr Microbiol 2016; 73:930-937. [PMID: 27686341 DOI: 10.1007/s00284-016-1141-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Accepted: 09/19/2016] [Indexed: 12/15/2022]
Abstract
Helicobacter pylori is a human-specific Gram-negative pathogenic bacterium which colonizes the gastric mucosal layer in the stomach causing diseases such as peptic ulcer, adenocarcinoma, and gastric lymphoma. It is estimated that approximately half of the world's population is infected with H. pylori making it the most intensively characterized microbial pathogen up to now. Hemolysis has been suggested to significantly contribute to colonization of the stomach and disease progression by H. pylori. In a number of earlier studies, TlyA was characterized as a putative pore-forming cytolysin. Although a few observations in the literature suggest a role for TlyA as significant virulence factor of H. pylori, the molecular and structural characterization of this protein is much curtailed at present. Given the intensive characterization of numerous H. pylori virulence factors over the past decade, surprisingly little information exists for the TlyA toxin and its significance for pathogenesis. This review provides a brief overview on microbial hemolysis and its role for pathogenesis and discusses recent research efforts aimed at an improved understanding of the role of the 'non-conventional' hemolysin and its associated RNA methyltransferase TlyA from H. pylori.
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Affiliation(s)
- Mohammad Bagher Javadi
- Bacterial Toxin Research Cluster, Institute of Molecular Biosciences, Mahidol University, Nakornpathom, 73170, Thailand
| | - Gerd Katzenmeier
- Bacterial Toxin Research Cluster, Institute of Molecular Biosciences, Mahidol University, Nakornpathom, 73170, Thailand.
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Mou KT, Muppirala UK, Severin AJ, Clark TA, Boitano M, Plummer PJ. A comparative analysis of methylome profiles of Campylobacter jejuni sheep abortion isolate and gastroenteric strains using PacBio data. Front Microbiol 2015; 5:782. [PMID: 25642218 PMCID: PMC4294202 DOI: 10.3389/fmicb.2014.00782] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Accepted: 12/20/2014] [Indexed: 12/13/2022] Open
Abstract
Campylobacter jejuni is a leading cause of human gastrointestinal disease and small ruminant abortions in the United States. The recent emergence of a highly virulent, tetracycline-resistant C. jejuni subsp. jejuni sheep abortion clone (clone SA) in the United States, and that strain's association with human disease, has resulted in a heightened awareness of the zoonotic potential of this organism. Pacific Biosciences' Single Molecule, Real-Time sequencing technology was used to explore the variation in the genome-wide methylation patterns of the abortifacient clone SA (IA3902) and phenotypically distinct gastrointestinal-specific C. jejuni strains (NCTC 11168 and 81-176). Several notable differences were discovered that distinguished the methylome of IA3902 from that of 11168 and 81-176: identification of motifs novel to IA3902, genome-specific hypo- and hypermethylated regions, strain level variability in genes methylated, and differences in the types of methylation motifs present in each strain. These observations suggest a possible role of methylation in the contrasting disease presentations of these three C. jejuni strains. In addition, the methylation profiles between IA3902 and a luxS mutant were explored to determine if variations in methylation patterns could be identified that might explain the role of LuxS-dependent methyl recycling in IA3902 abortifacient potential.
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Affiliation(s)
- Kathy T Mou
- Department of Veterinary Microbiology and Preventive Medicine, College of Veterinary Medicine, Iowa State University Ames, IA, USA
| | - Usha K Muppirala
- Genome Informatics Facility, Office of Biotechnology, Iowa State University Ames, IA, USA
| | - Andrew J Severin
- Genome Informatics Facility, Office of Biotechnology, Iowa State University Ames, IA, USA
| | | | | | - Paul J Plummer
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University Ames, IA, USA
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