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Chen W, Han LM, Chen XZ, Yi PC, Li H, Ren YY, Gao JH, Zhang CY, Huang J, Wang WX, Hu ZL, Hu CM. Engineered endolysin of Klebsiella pneumoniae phage is a potent and broad-spectrum bactericidal agent against "ESKAPEE" pathogens. Front Microbiol 2024; 15:1397830. [PMID: 38784808 PMCID: PMC11112412 DOI: 10.3389/fmicb.2024.1397830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2024] [Accepted: 04/22/2024] [Indexed: 05/25/2024] Open
Abstract
The rise of antimicrobial resistance in ESKAPEE pathogens poses significant clinical challenges, especially in polymicrobial infections. Bacteriophage-derived endolysins offer promise in combating this crisis, but face practical hurdles. Our study focuses on engineering endolysins from a Klebsiella pneumoniae phage, fusing them with ApoE23 and COG133 peptides. We assessed the resulting chimeric proteins' bactericidal activity against ESKAPEE pathogens in vitro. ApoE23-Kp84B (CHU-1) reduced over 3 log units of CFU for A. baumannii, E. faecalis, K. pneumoniae within 1 h, while COG133-Kp84B (CHU-2) showed significant efficacy against S. aureus. COG133-L1-Kp84B, with a GS linker insertion in CHU-2, exhibited outstanding bactericidal activity against E. cloacae and P. aeruginosa. Scanning electron microscopy revealed alterations in bacterial morphology after treatment with engineered endolysins. Notably, CHU-1 demonstrated promising anti-biofilm and anti-persister cell activity against A. baumannii and E. faecalis but had limited efficacy in a bacteremia mouse model of their coinfection. Our findings advance the field of endolysin engineering, facilitating the customization of these proteins to target specific bacterial pathogens. This approach holds promise for the development of personalized therapies tailored to combat ESKAPEE infections effectively.
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Affiliation(s)
- Wei Chen
- Department of Tuberculosis, The Second Hospital of Nanjing, Affiliated to Nanjing University of Chinese Medicine, Nanjing, China
| | - Li-Mei Han
- Department of Tuberculosis, The Second Hospital of Nanjing, Affiliated to Nanjing University of Chinese Medicine, Nanjing, China
- Clinical Research Center, The Second Hospital of Nanjing, Affiliated to Nanjing University of Chinese Medicine, Nanjing, China
| | - Xiu-Zhen Chen
- Department of Infectious Diseases, The Second Hospital of Nanjing, Affiliated to Nanjing University of Chinese Medicine, Nanjing, China
| | - Peng-Cheng Yi
- Department of Tuberculosis, The Second Hospital of Nanjing, Affiliated to Nanjing University of Chinese Medicine, Nanjing, China
| | - Hui Li
- Department of Laboratory Medicine, The Second Affiliated Hospital of Nanchang University, Nanchang, China
| | - Yun-Yao Ren
- Department of Tuberculosis, The Second Hospital of Nanjing, Affiliated to Nanjing University of Chinese Medicine, Nanjing, China
| | - Jing-Han Gao
- Clinical Research Center, The Second Hospital of Nanjing, Affiliated to Nanjing University of Chinese Medicine, Nanjing, China
| | - Cai-Yun Zhang
- Clinical Research Center, The Second Hospital of Nanjing, Affiliated to Nanjing University of Chinese Medicine, Nanjing, China
| | - Jing Huang
- Department of Clinical Laboratory, The Second Hospital of Nanjing, Affiliated to Nanjing University of Chinese Medicine, Nanjing, China
| | - Wei-Xiao Wang
- Department of Infectious Diseases, The Second Hospital of Nanjing, Affiliated to Nanjing University of Chinese Medicine, Nanjing, China
| | - Zhi-Liang Hu
- Department of Infectious Diseases, The Second Hospital of Nanjing, Affiliated to Nanjing University of Chinese Medicine, Nanjing, China
- Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Chun-Mei Hu
- Department of Tuberculosis, The Second Hospital of Nanjing, Affiliated to Nanjing University of Chinese Medicine, Nanjing, China
- Innovation Center for Infectious Diseases of Jiangsu Province, Nanjing, China
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Golosova NN, Matveev AL, Tikunova NV, Khlusevich YA, Kozlova YN, Morozova VV, Babkin IV, Ushakova TA, Zhirakovskaya EV, Panina EA, Ryabchikova EI, Tikunov AY. Bacteriophage vB_SepP_134 and Endolysin LysSte_134_1 as Potential Staphylococcus-Biofilm-Removing Biological Agents. Viruses 2024; 16:385. [PMID: 38543751 PMCID: PMC10975630 DOI: 10.3390/v16030385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 02/19/2024] [Accepted: 02/28/2024] [Indexed: 05/23/2024] Open
Abstract
Bacteria of the genus Staphylococcus are significant challenge for medicine, as many species are resistant to multiple antibiotics and some are even to all of the antibiotics we use. One of the approaches to developing new therapeutics to treat staphylococcal infections is the use of bacteriophages specific to these bacteria or the lytic enzymes of such bacteriophages, which are capable of hydrolyzing the cell walls of these bacteria. In this study, a new bacteriophage vB_SepP_134 (St 134) specific to Staphylococcus epidermidis was described. This podophage, with a genome of 18,275 bp, belongs to the Andhravirus genus. St 134 was able to infect various strains of 12 of the 21 tested coagulase-negative Staphylococcus species and one clinical strain from the Staphylococcus aureus complex. The genes encoding endolysin (LysSte134_1) and tail tip lysin (LysSte134_2) were identified in the St 134 genome. Both enzymes were cloned and produced in Escherichia coli cells. The endolysin LysSte134_1 demonstrated catalytic activity against peptidoglycans isolated from S. aureus, S. epidermidis, Staphylococcus haemolyticus, and Staphylococcus warneri. LysSte134_1 was active against S. aureus and S. epidermidis planktonic cells and destroyed the biofilms formed by clinical strains of S. aureus and S. epidermidis.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | - Artem Y. Tikunov
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of Russian Academy of Sciences, 630090 Novosibirsk, Russia; (N.N.G.); (N.V.T.); (Y.A.K.); (Y.N.K.); (V.V.M.); (I.V.B.); (T.A.U.); (E.A.P.); (E.I.R.)
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Golosova NN, Khlusevich YA, Morozova VV, Matveev AL, Kozlova YN, Tikunov AY, Panina EA, Tikunova NV. Characterization of a Thermostable Endolysin of the Aeribacillus Phage AeriP45 as a Potential Staphylococcus Biofilm-Removing Agent. Viruses 2024; 16:93. [PMID: 38257793 PMCID: PMC10819204 DOI: 10.3390/v16010093] [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: 11/22/2023] [Revised: 01/06/2024] [Accepted: 01/06/2024] [Indexed: 01/24/2024] Open
Abstract
Multidrug-resistant Gram-positive bacteria, including bacteria from the genus Staphylococcus, are currently a challenge for medicine. Therefore, the development of new antimicrobials is required. Promising candidates for new antistaphylococcal drugs are phage endolysins, including endolysins from thermophilic phages against other Gram-positive bacteria. In this study, the recombinant endolysin LysAP45 from the thermophilic Aeribacillus phage AP45 was obtained and characterized. The recombinant endolysin LysAP45 was produced in Escherichia coli M15 cells. It was shown that LysAP45 is able to hydrolyze staphylococcal peptidoglycans from five species and eleven strains. Thermostability tests showed that LysAP45 retained its hydrolytic activity after incubation at 80 °C for at least 30 min. The enzymatically active domain of the recombinant endolysin LysAP45 completely disrupted biofilms formed by multidrug-resistant S. aureus, S. haemolyticus, and S. epidermidis. The results suggested that LysAP45 is a novel thermostable antimicrobial agent capable of destroying biofilms formed by various species of multidrug-resistant Staphylococcus. An unusual putative cell-binding domain was found at the C-terminus of LysAP45. No domains with similar sequences were found among the described endolysins.
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Affiliation(s)
| | | | | | | | | | | | | | - Nina V. Tikunova
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, 630090 Novosibirsk, Russia; (N.N.G.); (V.V.M.); (A.L.M.); (Y.N.K.); (A.Y.T.); (E.A.P.)
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4
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Molchanov V, Yegorov A, Molchanov M, Timchenko A, Novikov V, Novojilov N, Timchenko M. Novel Antimicrobial Peptide from the Hepatopancreas of the Red King Crab. Int J Mol Sci 2023; 24:15607. [PMID: 37958589 PMCID: PMC10649287 DOI: 10.3390/ijms242115607] [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: 09/28/2023] [Revised: 10/17/2023] [Accepted: 10/23/2023] [Indexed: 11/15/2023] Open
Abstract
Crustaceans have successfully adapted to survive in their natural habitat, rich in microorganisms, due to the presence of antimicrobial peptides (AMPs) in their organism. They achieve this adaptation despite lacking the highly specific adaptive immune system found in vertebrates. One valuable source of AMPs is the hepatopancreas, a waste product from crab fishery and its processing. Applying zymographic and spectrophotometric techniques, we discovered a small peptide (approximately 5 kDa) within a low molecular weight protein fraction extracted from the acetone powder of the red king crab hepatopancreas. This peptide hydrolyzes both M. lysodeikticus cell wall and M. lysodeikticus cell wall polysaccharide, while showing no activity against gelatin. The found peptide may be of interest for application in medicine, biotechnology, and the food industry, for example as a bio-preservative.
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Affiliation(s)
- Vladislav Molchanov
- Institute of Theoretical and Experimental Biophysics RAS, Pushchino 142290, Russia; (V.M.); (A.Y.); (M.M.)
- National Research Nuclear University (NRNU) MEPhI Obninsk Institute for Nuclear Power Engineering (OINPE), Obninsk 249040, Russia
| | - Alexander Yegorov
- Institute of Theoretical and Experimental Biophysics RAS, Pushchino 142290, Russia; (V.M.); (A.Y.); (M.M.)
| | - Maxim Molchanov
- Institute of Theoretical and Experimental Biophysics RAS, Pushchino 142290, Russia; (V.M.); (A.Y.); (M.M.)
| | | | - Vitaly Novikov
- Polar Branch of Russian Federal Research Institute of Fisheries and Oceanography, Murmansk 183038, Russia;
| | - Nikolay Novojilov
- M. M. Shemyakin and Yu. A. Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow 117997, Russia;
| | - Maria Timchenko
- Institute of Theoretical and Experimental Biophysics RAS, Pushchino 142290, Russia; (V.M.); (A.Y.); (M.M.)
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Premetis GE, Georgakis ND, Stathi A, Labrou NE. Metaviromics analysis of marine biofilm reveals a glycoside hydrolase endolysin with high specificity towards Acinetobacter baumannii. BIOCHIMICA ET BIOPHYSICA ACTA. PROTEINS AND PROTEOMICS 2023; 1871:140918. [PMID: 37150474 DOI: 10.1016/j.bbapap.2023.140918] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Revised: 04/27/2023] [Accepted: 05/02/2023] [Indexed: 05/09/2023]
Abstract
Multidrug-resistant (MDR) bacteria are a growing threat to the public health. Among them, the Gram-negative Acinetobacter baumannii is considered today as the most dangerous MDR pathogen. Phage-derived endolysins are peptidoglycan (PG) hydrolytic enzymes that can function as effective tools in the fight against MDR bacteria. In the present work, the viral diversity of a marine environmental sample (biofilm), formed near an industrial zone, was mined for the identification of a putative endolysin (AbLys2) that belongs to the glycoside hydrolase family 24 (GH24, EC 3.2.1.17). The coding sequence of AbLys2 was cloned and expressed in E. coli. The lytic activity and specificity of the recombinant enzyme were evaluated against suspensions of a range of Gram-positive and Gram-negative human pathogens using turbidity assays. AbLys2 displayed enhanced selectivity towards A. baumannii cells, compared to other bacteria. Kinetics analysis was carried out to characterize the dependence of its lytic activity on pH and showed that the enzyme exhibits its maximal activity at pH 5.5. Thermostability analysis showed that AbLys2 displays melting temperature Tm 47.1 °C. Florescence microscopy and cell viability assays established that AbLys2 is active towards live cultures of A. baumannii cells with an inhibitory concentration IC50 3.41 ± 0.09 μM. Molecular modeling allowed the prediction of important amino acid residues involved in catalysis. The results of the present study suggest that AbLys2 provides efficient lytic and antimicrobial activity towards A. baumannii cells and therefore is a promising new antimicrobial against this pathogen.
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Affiliation(s)
- Georgios E Premetis
- Laboratory of Enzyme Technology, Department of Biotechnology, School of Applied Biology and Biotechnology, Agricultural University of Athens, 75 Iera Odos Street, GR-11855 -Athens, Greece
| | - Nikolaos D Georgakis
- Laboratory of Enzyme Technology, Department of Biotechnology, School of Applied Biology and Biotechnology, Agricultural University of Athens, 75 Iera Odos Street, GR-11855 -Athens, Greece
| | - Angeliki Stathi
- Department of Microbiology, "Aghia Sophia" Children's Hospital, 11527 Athens, Greece
| | - Nikolaos E Labrou
- Laboratory of Enzyme Technology, Department of Biotechnology, School of Applied Biology and Biotechnology, Agricultural University of Athens, 75 Iera Odos Street, GR-11855 -Athens, Greece.
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Varotsou C, Premetis GE, Labrou NE. Characterization and Engineering Studies of a New Endolysin from the Propionibacterium acnes Bacteriophage PAC1 for the Development of a Broad-Spectrum Artilysin with Altered Specificity. Int J Mol Sci 2023; 24:ijms24108523. [PMID: 37239874 DOI: 10.3390/ijms24108523] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 04/27/2023] [Accepted: 05/04/2023] [Indexed: 05/28/2023] Open
Abstract
The emergence of multidrug-resistant (MDR) bacteria has risen rapidly, leading to a great threat to global public health. A promising solution to this problem is the exploitation of phage endolysins. In the present study, a putative N-acetylmuramoyl-L-alanine type-2 amidase (NALAA-2, EC 3.5.1.28) from Propionibacterium bacteriophage PAC1 was characterized. The enzyme (PaAmi1) was cloned into a T7 expression vector and expressed in E. coli BL21 cells. Kinetics analysis using turbidity reduction assays allowed the determination of the optimal conditions for lytic activity against a range of Gram-positive and negative human pathogens. The peptidoglycan degradation activity of PaAmi1 was confirmed using isolated peptidoglycan from P. acnes. The antibacterial activity of PaAmi1 was investigated using live P. acnes cells growing on agar plates. Two engineered variants of PaAmi1 were designed by fusion to its N-terminus two short antimicrobial peptides (AMPs). One AMP was selected by searching the genomes of Propionibacterium bacteriophages using bioinformatics tools, whereas the other AMP sequence was selected from the antimicrobial peptide databases. Both engineered variants exhibited improved lytic activity towards P. acnes and the enterococci species Enterococcus faecalis and Enterococcus faecium. The results of the present study suggest that PaAmi1 is a new antimicrobial agent and provide proof of concept that bacteriophage genomes are a rich source of AMP sequences that can be further exploited for designing novel or improved endolysins.
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Affiliation(s)
- Christina Varotsou
- Laboratory of Enzyme Technology, Department of Biotechnology, School of Applied Biology and Biotechnology, Agricultural University of Athens, 75 Iera Odos Street, 11855 Athens, Greece
| | - Georgios E Premetis
- Laboratory of Enzyme Technology, Department of Biotechnology, School of Applied Biology and Biotechnology, Agricultural University of Athens, 75 Iera Odos Street, 11855 Athens, Greece
| | - Nikolaos E Labrou
- Laboratory of Enzyme Technology, Department of Biotechnology, School of Applied Biology and Biotechnology, Agricultural University of Athens, 75 Iera Odos Street, 11855 Athens, Greece
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Ser/Thr Kinase-Dependent Phosphorylation of the Peptidoglycan Hydrolase CwlA Controls Its Export and Modulates Cell Division in Clostridioides difficile. mBio 2021; 12:mBio.00519-21. [PMID: 34006648 PMCID: PMC8262956 DOI: 10.1128/mbio.00519-21] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Cell growth and division require a balance between synthesis and hydrolysis of the peptidoglycan (PG). Inhibition of PG synthesis or uncontrolled PG hydrolysis can be lethal for the cells, making it imperative to control peptidoglycan hydrolase (PGH) activity. The synthesis or activity of several key enzymes along the PG biosynthetic pathway is controlled by the Hanks-type serine/threonine kinases (STKs). In Gram-positive bacteria, inactivation of genes encoding STKs is associated with a range of phenotypes, including cell division defects and changes in cell wall metabolism, but only a few kinase substrates and associated mechanisms have been identified. We previously demonstrated that STK-PrkC plays an important role in cell division, cell wall metabolism, and resistance to antimicrobial compounds in the human enteropathogen Clostridioides difficile In this work, we characterized a PG hydrolase, CwlA, which belongs to the NlpC/P60 family of endopeptidases and hydrolyses cross-linked PG between daughter cells to allow cell separation. We identified CwlA as the first PrkC substrate in C. difficile We demonstrated that PrkC-dependent phosphorylation inhibits CwlA export, thereby controlling hydrolytic activity in the cell wall. High levels of CwlA at the cell surface led to cell elongation, whereas low levels caused cell separation defects. Thus, we provided evidence that the STK signaling pathway regulates PGH homeostasis to precisely control PG hydrolysis during cell division.IMPORTANCE Bacterial cells are encased in a PG exoskeleton that helps to maintain cell shape and confers physical protection. To allow bacterial growth and cell separation, PG needs to be continuously remodeled by hydrolytic enzymes that cleave PG at critical sites. How these enzymes are regulated remains poorly understood. We identify a new PG hydrolase involved in cell division, CwlA, in the enteropathogen C. difficile Lack or accumulation of CwlA at the bacterial surface is responsible for a division defect, while its accumulation in the absence of PrkC also increases susceptibility to antimicrobial compounds targeting the cell wall. CwlA is a substrate of the kinase PrkC in C. difficile PrkC-dependent phosphorylation controls the export of CwlA, modulating its levels and, consequently, its activity in the cell wall. This work provides a novel regulatory mechanism by STK in tightly controlling protein export.
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Nie T, Meng F, Zhou L, Lu F, Bie X, Lu Z, Lu Y. In Silico Development of Novel Chimeric Lysins with Highly Specific Inhibition against Salmonella by Computer-Aided Design. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2021; 69:3751-3760. [PMID: 33565867 DOI: 10.1021/acs.jafc.0c07450] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Four novel chimeric lysins (P361, P362, P371, and P372), which were the fusion of Salmonella phage lysins and novel antimicrobial peptide LeuA-P, were obtained using bioinformatics analysis and in silico design. The recombinant chimeric lysins were expressed in E. coli BL21(DE3) strain and showed highly specific inhibition against Salmonella. The minimal inhibitory concentrations (MICs) of P362 and P372 to S. typhi CMCC 50071 were 8 and 16 μg/mL, respectively. Both 1 × MIC P362 and P372 could increase the outer membrane permeability and cleave the cell wall peptidoglycan, causing the leakage of intracellular nucleic acids and proteins and ultimately killing Salmonella efficiently without drug resistance. The combination of P362, P372, and potassium sorbate reduced more than 3 log CFU/g counts of microorganisms in contaminated chilled chicken and extended the shelf life by 7 days. The strategy of antimicrobial peptide (AMP)-lysin chimera inspired the inability of phage lysin to specifically inhibit Gram-negative bacteria with dense outer membranes in vitro.
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Affiliation(s)
- Ting Nie
- College of Food Science and Technology, Nanjing Agricultural University, Nanjing, Jiangsu Province 210095, China
| | - Fanqiang Meng
- College of Food Science and Technology, Nanjing Agricultural University, Nanjing, Jiangsu Province 210095, China
| | - Libang Zhou
- College of Food Science and Technology, Nanjing Agricultural University, Nanjing, Jiangsu Province 210095, China
| | - Fengxia Lu
- College of Food Science and Technology, Nanjing Agricultural University, Nanjing, Jiangsu Province 210095, China
| | - Xiaomei Bie
- College of Food Science and Technology, Nanjing Agricultural University, Nanjing, Jiangsu Province 210095, China
| | - Zhaoxin Lu
- College of Food Science and Technology, Nanjing Agricultural University, Nanjing, Jiangsu Province 210095, China
| | - Yingjian Lu
- College of Food Science and Engineering, Nanjing University of Finance and Economics, Nanjing, Jiangsu Province 210023, China
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Burkholderia thailandensis outer membrane vesicles exert antimicrobial activity against drug-resistant and competitor microbial species. J Microbiol 2020; 58:550-562. [DOI: 10.1007/s12275-020-0028-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 03/03/2020] [Accepted: 03/09/2020] [Indexed: 12/21/2022]
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10
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Identification and Characterization of a Cell Wall Hydrolase for Sporangiospore Maturation in Actinoplanes missouriensis. J Bacteriol 2019; 201:JB.00519-19. [PMID: 31570527 DOI: 10.1128/jb.00519-19] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Accepted: 09/23/2019] [Indexed: 11/20/2022] Open
Abstract
The rare actinomycete Actinoplanes missouriensis grows as substrate mycelium and forms terminal sporangia containing a few hundred spores as dormant cells. Upon contact with water, the sporangia open up and release spores to external environments. Here, we report a cell wall hydrolase, GsmA, that is required for sporangiospore maturation in A. missouriensis The gsmA gene is conserved among Actinoplanes species and several species of other rare actinomycetes. Transcription of gsmA is activated in the late stage of sporangium formation by the global transcriptional activator TcrA, which is involved in sporangium formation and dehiscence. GsmA is composed of an N-terminal signal peptide for the twin arginine translocation pathway, two tandem bacterial SH3-like domains, and a glucosaminidase domain. Zymographic analysis using a recombinant C-terminal glucosaminidase domain protein showed that GsmA is a hydrolase able to digest cell walls extracted from the vegetative mycelia of A. missouriensis and Streptomyces griseus A gsmA deletion mutant (ΔgsmA) formed apparently normal sporangia, but they released chains of 2 to 20 spores under sporangium dehiscence-inducing conditions, indicating that spores did not completely mature in the mutant sporangia. From these results, we concluded that GsmA is a cell wall hydrolase for digesting peptidoglycan at septum-forming sites to separate adjacent spores during sporangiospore maturation in A. missouriensis Unexpectedly, flagella were observed around the spore chains of the ΔgsmA mutant by transmission electron microscopy. The flagellar formation was strictly restricted to cell-cell interfaces, giving an important insight into the polarity of the flagellar biogenesis in a spherical spore.IMPORTANCE In streptomycetes, an aerial hypha is compartmentalized by multiple septations into prespores, which become spores through a series of maturation processes. However, little is known about these maturation processes. The rare actinomycete Actinoplanes missouriensis produces sporangiospores, which are assumed to be formed also from prespores generated by the compartmentalization of intrasporangium hyphae via septation. The identification of GsmA as a cell wall hydrolase for the separation of adjacent spores sheds light on the almost unknown processes of sporangiospore formation in A. missouriensis Furthermore, the fact that GsmA orthologues are conserved within the genus Actinoplanes but not in streptomycetes indicates that Actinoplanes has developed an original strategy for the spore maturation in a specific environment, that is, inside a sporangium.
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A novel thermophilic Aeribacillus bacteriophage AP45 isolated from the Valley of Geysers, Kamchatka: genome analysis suggests the existence of a new genus within the Siphoviridae family. Extremophiles 2019; 23:599-612. [PMID: 31376001 DOI: 10.1007/s00792-019-01119-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Accepted: 07/21/2019] [Indexed: 12/12/2022]
Abstract
A novel thermophilic bacteriophage AP45 and its host strain Aeribacillus sp. CEMTC656 were isolated from the Valley of Geysers, Kamchatka Peninsula, Russia. Bacteriophage AP45 was identified as a member of the Siphoviridae family by electron microscopy. It showed high thermostability and had a slow cycle of reproduction. The AP45 genome had 51,606 base pairs (bp) and contained 71 open reading frames (ORFs), 40 of them encoding proteins of predicted function. Genes encoding DNA and RNA polymerases were not identified, indicating that AP45 used host polymerases. Based on the ORF65 encoding putative endolysin, the recombinant protein rAP45Lys was developed and its peptidoglycan-hydrolyzing activity was demonstrated. The AP45 genome exhibited limited identity to other phage sequences; the highest identity, 36%, was with the genome of the thermophilic Geobacillus myovirus D6E. The majority of putative proteins encoded by the AP45 genome had higher similarity to proteins from bacteria belonging to the Bacillaceae family, than to bacteriophages. In addition, more than half of the putative ORFs in the AP45 genome were highly similar to prophage sequences of A. pallidus strain 8m3, which was isolated in north-east China. The AP45 phage and revealed prophages might be members of a new genus belonging to the Siphoviridae family.
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Fukushima T, Uchida N, Ide M, Kodama T, Sekiguchi J. DL-endopeptidases function as both cell wall hydrolases and poly-γ-glutamic acid hydrolases. MICROBIOLOGY-SGM 2018; 164:277-286. [PMID: 29458655 DOI: 10.1099/mic.0.000609] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Biopolymers on the cell surface are very important for protecting microorganisms from environmental stresses, as well as storing nutrients and minerals. Synthesis of biopolymers is well studied, while studies on the modification and degradation processes of biopolymers are limited. One of these biopolymers, poly-γ-glutamic acid (γ-PGA), is produced by Bacillus species. Bacillus subtilis PgdS, possessing three NlpC/P60 domains, hydrolyses γ-PGA. Here, we have demonstrated that several dl-endopeptidases with an NlpC/P60 domain (LytE, LytF, CwlS, CwlO, and CwlT) in B. subtilis digest not only an amide bond of d-γ-glutamyl-diaminopimelic acid in peptidoglycans but also linkages of γ-PGA produced by B. subtilis. The hydrolase activity of dl-endopeptidases towards γ-PGA was inhibited by IseA, which also inhibits their hydrolase activity towards peptidoglycans, while the hydrolysis of PgdS towards γ-PGA was not inhibited. PgdS hydrolysed only the d-/l-Glu‒d-Glu linkages of d-Glu-rich γ-PGA (d-Glu:l-Glu=7 : 3) and l-Glu-rich γ-PGA (d-Glu:l-Glu=1 : 9), indicating that PgdS can hydrolyse only restricted substrates. On the other hand, the dl-endopeptidases in B. subtilis cleaved d-/l-Glu‒d-/l-Glu linkages of d-Glu-rich γ-PGA (d-Glu:l-Glu=7 : 3), indicating that these enzymes show different substrate specificities. Thus, the dl-endopeptidases digest γ-PGA more flexibly than PgdS, even though they are annotated as "dl-endopeptidase, digesting the d-γ-glutamyl-diaminopimelic acid linkage (d‒l amino acid bond)".
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Affiliation(s)
- Tatsuya Fukushima
- Division of Gene Research, Department of Life Sciences, Research Center for Human and Environmental Sciences, Shinshu University, 3-15-1 Tokida, Ueda, Nagano 386-8567, Japan.,Present address: Fornia Biosolutions, Inc., 3876 Bay Center Place, Hayward, CA 94545, USA
| | - Natsuki Uchida
- Department of Applied Biology, Graduate School of Science and Technology, Shinshu University, 3-15-1 Tokida, Ueda-shi, Nagano 386-8567, Japan
| | - Masatoshi Ide
- Department of Applied Biology, Graduate School of Science and Technology, Shinshu University, 3-15-1 Tokida, Ueda-shi, Nagano 386-8567, Japan
| | - Takeko Kodama
- Kao Corporation, Biological Science Research, 1334 Minato, Wakayama-shi, Wakayama 640-8580, Japan
| | - Junichi Sekiguchi
- Department of Applied Biology, Graduate School of Science and Technology, Shinshu University, 3-15-1 Tokida, Ueda-shi, Nagano 386-8567, Japan
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