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Wei N, Zha F, Zhou L, Xu H, Liu Z, Meng Q, Zhu T, Yin J, Yu Z. ppGpp is a dual-role regulator involved in balancing iron absorption and prodiginine biosynthesis in Pseudoalteromonas. Mol Microbiol 2024; 122:68-80. [PMID: 38845079 DOI: 10.1111/mmi.15285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Revised: 04/26/2024] [Accepted: 05/29/2024] [Indexed: 07/21/2024]
Abstract
Iron is an essential element for microbial survival and secondary metabolism. However, excess iron availability and overloaded secondary metabolites can hinder microbial growth and survival. Microorganisms must tightly control iron homeostasis and secondary metabolism. Our previous studies have found that the stringent starvation protein A (SspA) positively regulates prodiginine biosynthesis by activating iron uptake in Pseudoalteromonas sp. strain R3. It is believed that the interaction between SspA and the small nucleotide ppGpp is important for iron to exert regulation functions. However, the roles of ppGpp in iron absorption and prodiginine biosynthesis, and the underlying relationship between ppGpp and SspA in strain R3 remain unclear. In this study, we found that ppGpp accumulation in strain R3 could be induced by limiting iron. In addition, ppGpp not only positively regulated iron uptake and prodiginine biosynthesis via increasing the SspA level but also directly repressed iron uptake and prodiginine biosynthesis independent of SspA, highlighting the finding that ppGpp can stabilize both iron levels and prodiginine production. Notably, the abolishment of ppGpp significantly increased prodiginine production, thus providing a theoretical basis for manipulating prodiginine production in the future. This dynamic ppGpp-mediated interaction between iron uptake and prodiginine biosynthesis has significant implications for understanding the roles of nutrient uptake and secondary metabolism for the survival of bacteria in unfavorable environments.
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Affiliation(s)
- Ning Wei
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, Zhejiang Province, China
| | - Fanglan Zha
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, Zhejiang Province, China
| | - Luosai Zhou
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, Zhejiang Province, China
| | - Hongyang Xu
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, Zhejiang Province, China
| | - Zhuangzhuang Liu
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, Zhejiang Province, China
| | - Qiu Meng
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, Zhejiang Province, China
| | - Tingheng Zhu
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, Zhejiang Province, China
| | - Jianhua Yin
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, Zhejiang Province, China
| | - Zhiliang Yu
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, Zhejiang Province, China
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Wang X, Li H, Wu C, Yang J, Wang J, Yang T. Metabolism-triggered sensor array aided by machine learning for rapid identification of pathogens. Biosens Bioelectron 2024; 255:116264. [PMID: 38588629 DOI: 10.1016/j.bios.2024.116264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Revised: 03/28/2024] [Accepted: 03/31/2024] [Indexed: 04/10/2024]
Abstract
Chemical-nose strategy has achieved certain success in the discrimination and identification of pathogens. However, this strategy usually relies on non-specific interactions, which are prone to be significantly disturbed by the change of environment thus limiting its practical usefulness. Herein, we present a novel chemical-nose sensing approach leveraging the difference in the dynamic metabolic variation during peptidoglycan metabolism among different species for rapid pathogen discrimination. Pathogens were first tethered with clickable handles through metabolic labeling at two different acidities (pH = 5 and 7) for 20 and 60 min, respectively, followed by click reaction with fluorescence up-conversion nanoparticles to generate a four-dimensional signal output. This discriminative multi-dimensional signal allowed eight types of model bacteria to be successfully classified within the training set into strains, genera, and Gram phenotypes. As the difference in signals of the four sensing channels reflects the difference in the amount/activity of enzymes involved in metabolic labeling, this strategy has good anti-interference capability, which enables precise pathogen identification within 2 h with 100% accuracy in spiked urinary samples and allows classification of unknown species out of the training set into the right phenotype. The robustness of this approach holds significant promise for its widespread application in pathogen identification and surveillance.
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Affiliation(s)
- Xin Wang
- Research Center for Analytical Sciences, Department of Chemistry, College of Sciences, Northeastern University, Shenyang 110819, China
| | - Huida Li
- Research Center for Analytical Sciences, Department of Chemistry, College of Sciences, Northeastern University, Shenyang 110819, China
| | - Chengxin Wu
- State Key Laboratory of Primate Biomedical Research, Institute of Primate Translational Medicine, Kunming University of Science and Technology, Kunming, 650500, China
| | - Jianyu Yang
- School of Materials Science and Engineering, Suzhou University of Science and Technology, Suzhou, 215009, China
| | - Jianhua Wang
- Research Center for Analytical Sciences, Department of Chemistry, College of Sciences, Northeastern University, Shenyang 110819, China
| | - Ting Yang
- Research Center for Analytical Sciences, Department of Chemistry, College of Sciences, Northeastern University, Shenyang 110819, China.
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Ren Y, Liu R, Zheng Y, Wang H, Meng Q, Zhu T, Yin J, Cao X, Yu Z. Biosynthetic mechanism of the yellow pigments in the marine bacterium Pseudoalteromonas sp. strain T1lg65. Appl Environ Microbiol 2024; 90:e0177923. [PMID: 38193673 PMCID: PMC10880671 DOI: 10.1128/aem.01779-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Accepted: 11/28/2023] [Indexed: 01/10/2024] Open
Abstract
The Pseudoalteromonas genus marine bacteria have attracted increasing interest because of their abilities to produce bioactive metabolites. The pigmented Pseudoalteromonas group encodes more secondary metabolite biosynthetic gene clusters (BGCs) than the non-pigmented group. Here, we report a yellow pigmented bacterium Pseudoalteromonas sp. strain T1lg65, which was isolated from a mangrove forest sediment. We showed that the yellow pigments of T1lg65 belong to the group of lipopeptide alterochromides. Further genetic analyses of the alterochromide BGC revealed that the yellow pigments are biosynthesized by aryl-polyene synthases and nonribosomal peptide synthases. Within the gene cluster, altA encodes a tyrosine ammonia acid lyase, which catalyzes synthesis of the precursor 4-hydroxycinnamic acid (4-HCA) from tyrosine in the alterochromide biosynthetic pathway. In addition, altN, encoding a putative flavin-dependent halogenase, was proven to be responsible for the bromination of alterochromides based on gene deletion, molecular docking, and site mutagenesis analyses. In summary, the biosynthetic pathway, precursor synthesis, and bromination mechanism of the lipopeptide alterochromides were studied in-depth. Our results expand the knowledge on biosynthesis of Pseudoalteromonas pigments and could promote the development of active pigments in the future.IMPORTANCEThe marine bacteria Pseudoalteromonas spp. are important biological resources because they are producers of bioactive natural products, including antibiotics, pigments, enzymes, and antimicrobial peptides. One group of the microbial pigments, alterochromides, holds a great value for their novel lipopeptide structures and antimicrobial activities. Previous studies were limited to the structural characterization of alterochromides and genome mining for the alterochromide biosynthesis. This work focused on the biosynthetic mechanism for alterochromide production, especially revealing functions of two key genes within the gene cluster for the alterochromide biosynthesis. On the one hand, our study provides a target for metabolic engineering of the alterochromide biosynthesis; on the other hand, the 4-HCA synthase AltA and brominase AltN show potential in the biocatalyst industry.
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Affiliation(s)
- Yixuan Ren
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Ruoyu Liu
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Yifan Zheng
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Hang Wang
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Qiu Meng
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Tingheng Zhu
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Jianhua Yin
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Xueqiang Cao
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Zhiliang Yu
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
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Wang Y, Wu Z, Wang Z, Du H, Xiao S, Lu L, Wang Z. Analyses of the Antibiofilm Activity of o-Phenanthroline Monohydrate against Enterococcus faecalis and Staphylococcus aureus and the Mechanisms Underlying These Effects. ACS Infect Dis 2024; 10:638-649. [PMID: 38258383 DOI: 10.1021/acsinfecdis.3c00516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
Enterococcus faecalis and Staphylococcus aureus exhibit robust biofilm formation capabilities, the formation of which is closely linked to pathogenicity and drug resistance, thereby resulting in host infection and treatment failure. o-Phenanthroline monohydrate (o-Phen) and its derivatives demonstrate a wide range of antibacterial and antifungal activities. In this study, we aimed to explore the antibiofilm activity of o-Phen to E. faecalis and S. aureus and provide insights into the molecular mechanisms for combating biofilm resistance. We demonstrated that o-Phen possesses significant antibacterial and antibiofilm properties against E. faecalis and S. aureus, inducing alterations in bacterial morphology, compromising cell membrane integrity, and exhibiting synergistic effects with β-lactam antibiotics at sub-MIC concentrations. The adhesion ability and automatic condensation capacity of, and synthesis of, extracellular polymers by E. faecalis cells were reduced by o-Phen, resulting in the inhibition of biofilm formation. Importantly, transcriptome analysis revealed 354 upregulated and 456 downregulated genes in o-Phen-treated E. faecalis. Differentially expressed genes were enriched in 11 metabolism-related pathways, including amino acid metabolism, pyrimidine metabolism, and glycolysis/gluconeogenesis. Moreover, the oppA, CeuA, and ZnuB genes involved in the ABC transport system, and the PBP1A penicillin-binding protein-coding genes sarA and mrcA were significantly downregulated. The multidrug efflux pump system and membrane permeability genes mdtG and hlyD, and bacterial adhesion-related genes, including adcA and fss2 were also downregulated, while mraZ and ASP23 were upregulated. Thus, o-Phen is anticipated to be an effective alternative drug for the treatment of E. faecalis and S. aureus biofilm-associated infections.
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Affiliation(s)
- Yu Wang
- Beijing Key Laboratory of Traditional Chinese Veterinary Medicine, Animal Science and Technology College, Beijing University of Agriculture, Beijing 102206, China
| | - Zhouhui Wu
- Beijing Key Laboratory of Traditional Chinese Veterinary Medicine, Animal Science and Technology College, Beijing University of Agriculture, Beijing 102206, China
| | - Zhiwen Wang
- Beijing Key Laboratory of Traditional Chinese Veterinary Medicine, Animal Science and Technology College, Beijing University of Agriculture, Beijing 102206, China
| | - Heng Du
- Beijing Key Laboratory of Traditional Chinese Veterinary Medicine, Animal Science and Technology College, Beijing University of Agriculture, Beijing 102206, China
| | - Shuang Xiao
- Beijing Key Laboratory of Traditional Chinese Veterinary Medicine, Animal Science and Technology College, Beijing University of Agriculture, Beijing 102206, China
| | - Lin Lu
- Beijing Key Laboratory of Traditional Chinese Veterinary Medicine, Animal Science and Technology College, Beijing University of Agriculture, Beijing 102206, China
| | - Zhen Wang
- Beijing Key Laboratory of Traditional Chinese Veterinary Medicine, Animal Science and Technology College, Beijing University of Agriculture, Beijing 102206, China
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Ameji PJ, Uzairu A, Shallangwa GA, Uba S. Molecular docking-based virtual screening, drug-likeness, and pharmacokinetic profiling of some anti- Salmonella typhimurium cephalosporin derivatives. J Taibah Univ Med Sci 2023; 18:1417-1431. [PMID: 38162870 PMCID: PMC10757315 DOI: 10.1016/j.jtumed.2023.05.021] [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: 12/03/2022] [Revised: 04/25/2023] [Accepted: 05/31/2023] [Indexed: 01/03/2024] Open
Abstract
Objective The rising cases of resistance to existing antibiotic therapies in Salmonella typhimurium has made it necessary to search for novel drug candidates. The present study employed the molecular docking technique to screen a set of antibacterial cephalosporin analogues against penicillin-binding protein 1a (PBP1a) of the bacterium. This is the first study to screen cephalosporin analogues against PBP1a, a protein central to peptidoglycan synthesis in S. typhimurium. Methods Some cephalosporin analogues were retrieved from a drug repository. The structures of the molecules were optimized using the semi-empirical method of Spartan 14 software and were subsequently docked against the active sites of PBP1a using AutoDock vina software. The most potent ligands were chosen as the most promising leads and subsequently subjected to absorption, distribution, metabolism, excretion, and toxicity (ADMET) profiling using the SwissADME online server and DataWarrior chemoinformatics program. The CABSflex 2.0 server was used to carry out molecular dynamics (MD) simulation on the most stable ligand-protein complex. Results Compounds 3, 23, and 28 with binding affinity (ΔG) values of -9.2, -8.7, and -8.9 kcal/mol, respectively, were selected as the most promising leads. The ligands bound to the active sites of PBP1a via hydrophobic bonds, hydrogen bonds, and electrostatic interactions. Furthermore, ADMET analyses of the ligands revealed that they exhibited sound pharmacokinetic and toxicity profiles. In addition, an MD study revealed that the most active ligand bound favorably and dynamically to the target protein. Conclusion The findings of this research could provide an excellent platform for the discovery and rational design of novel antibiotics against S. typhimurium. Additional in vitro and in vivo studies should be carried out on the drug candidates to validate the findings of this study.
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Affiliation(s)
- Philip John Ameji
- Department of Chemistry, Federal University Lokoja, Lokoja, Kogi State, Nigeria
| | - Adamu Uzairu
- Department of Chemistry, Ahmadu Bello University, Zaria, Kaduna State, Nigeria
| | | | - Sani Uba
- Department of Chemistry, Ahmadu Bello University, Zaria, Kaduna State, Nigeria
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Lou J, Cai J, Hu X, Liang Y, Sun Y, Zhu Y, Meng Q, Zhu T, Gao H, Yu Z, Yin J. The stringent starvation protein SspA modulates peptidoglycan synthesis by regulating the expression of peptidoglycan synthases. Mol Microbiol 2022; 118:716-730. [PMID: 36308522 DOI: 10.1111/mmi.14996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Revised: 10/19/2022] [Accepted: 10/22/2022] [Indexed: 01/18/2023]
Abstract
The peptidoglycan (PG) layer of bacterial cells is essential for maintaining the cell shape and survival of cells; therefore, the synthesis of PG needs to be spatiotemporally controlled. While it is well established that PG synthesis is mediated posttranslationally through interactions between PG synthases and their cognate partners, much less is known about the transcriptional regulation of genes encoding these synthases. Based on a previous finding that the Gram-negative bacterium Shewanella oneidensis lacking the prominent PG synthase exhibits impaired cell wall integrity, we performed genetic selections to isolate the suppressors. We discovered that disrupting the sspA gene encoding stringent starvation protein A (SspA) is sufficient to suppress compromised PG. SspA serves as a transcriptional repressor that regulates the expression of the two types of PG synthases, class A penicillin-binding proteins and SEDS/bPBP protein complexes. SspA is an RNA polymerase-associated protein, and its regulation involves interactions with the σ70 -RNAP complex and an antagonistic effect of H-NS, a global nucleoid-associated protein. We also present evidence that the regulation of PG synthases by SspA is conserved in Escherichia coli, adding a new dimension to the current understanding of PG synthesis and its regulation.
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Affiliation(s)
- Jie Lou
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Jingxiao Cai
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Xiao Hu
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Yanqun Liang
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Yijuan Sun
- College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Yiling Zhu
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Qiu Meng
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Tingheng Zhu
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Haichun Gao
- College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Zhiliang Yu
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Jianhua Yin
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
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The penicillin binding protein 1A of Helicobacter pylori, its amoxicillin binding site and access routes. Gut Pathog 2021; 13:43. [PMID: 34183046 PMCID: PMC8240269 DOI: 10.1186/s13099-021-00438-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Accepted: 06/15/2021] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Amoxicillin-resistant H. pylori strains are increasing worldwide. To explore the potential resistance mechanisms involved, the 3D structure modeling and access tunnel prediction for penicillin-binding proteins (PBP1A) was performed, based on the Streptococcus pneumoniae, PBP 3D structure. Molecular covalent docking was used to determine the interactions between amoxicillin (AMX) and PBP1A. RESULTS The AMX-Ser368 covalent complex interacts with the binding site residues (Gly367, Ala369, ILE370, Lys371, Tyr416, Ser433, Thr541, Thr556, Gly557, Thr558, and Asn560) of PBP1A, non-covalently. Six tunnel-like structures, accessing the PBP1A binding site, were characterized, using the CAVER algorithm. Tunnel-1 was the ultimate access route, leading to the drug catalytic binding residue (Ser368). This tunnel comprises of eighteen amino acid residues, 8 of which are shared with the drug binding site. Subsequently, to screen the presence of PBP1A mutations, in the binding site and tunnel residues, in our clinical strains, in vitro assays were performed. H. pylori strains, isolated under gastroscopy, underwent AMX susceptibility testing by E-test. Of the 100 clinical strains tested, 4 were AMX-resistant. The transpeptidase domain of the pbp1a gene of these resistant, plus 10 randomly selected AMX-susceptible strains, were amplified and sequenced. Of the amino acids lining the tunnel-1 and binding site residues, three (Ser414Arg, Val469Met and Thr556Ser) substitutions, were detected in 2 of the 4 resistant and none of the sequenced susceptible strains, respectively. CONCLUSIONS We hypothesize that mutations in amino acid residues lining the binding site and/or tunnel-1, resulting in conformational/spatial changes, may block drug binding to PBP1A and cause AMX resistance.
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The LuxI/LuxR-Type Quorum Sensing System Regulates Degradation of Polycyclic Aromatic Hydrocarbons via Two Mechanisms. Int J Mol Sci 2020; 21:ijms21155548. [PMID: 32756387 PMCID: PMC7432010 DOI: 10.3390/ijms21155548] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 07/24/2020] [Accepted: 07/31/2020] [Indexed: 01/20/2023] Open
Abstract
Members of the Sphingomonadales are renowned for their ability to degrade polycyclic aromatic hydrocarbons (PAHs). However, little is known about the regulatory mechanisms of the degradative pathway. Using cross-feeding bioassay, a functional LuxI/LuxR-type acyl-homoserine lactone (AHL)-mediated quorum sensing (QS) system was identified from Croceicoccus naphthovorans PQ-2, a member of the order Sphingomonadales. Inactivation of the QS system resulted in a significant decrease in PAHs degradation. The QS system positively controlled the expression of three PAH-degrading genes (ahdA1e, xylE and xylG) and a regulatory gene ardR, which are located on the large plasmid. Interestingly, the transcription levels of these three PAH-degrading genes were significantly down-regulated in the ardR mutant. In addition, bacterial cell surface hydrophobicity and cell morphology were altered in the QS-deficient mutant. Therefore, the QS system in strain PQ-2 positively regulates PAH degradation via two mechanisms: (i) by induction of PAH-degrading genes directly and/or indirectly; and (ii) by an increase of bacterial cell surface hydrophobicity. The findings of this study improve our understanding of how the QS system influences the degradation of PAHs, therefore facilitating the development of new strategies for the bioremediation of PAHs.
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