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Soysa HSM, Kumsaoad S, Amornloetwattana R, Watanabe T, Suginta W. Single-channel characterization of the chitooligosaccharide transporter chitoporin (SmChiP) from the opportunistic pathogen Serratia marcescens. J Biol Chem 2022; 298:102487. [PMID: 36113582 PMCID: PMC9582717 DOI: 10.1016/j.jbc.2022.102487] [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: 05/01/2022] [Revised: 09/08/2022] [Accepted: 09/10/2022] [Indexed: 11/25/2022] Open
Abstract
Serratia marcescens is an opportunistic pathogen that can utilize chitin as a carbon source, through its ability to produce chitin-degrading enzymes to digest chitin and membrane transporters to transport the degradation products (chitooligosaccharides) into the cells. Further characterization of these proteins is important to understand details of chitin metabolism. Here, we investigate the properties and function of the S. marcescens chitoporin, namely SmChiP, a chitooligosaccharide transporter. We show that SmChiP is a monomeric porin that forms a stable channel in artificial phospholipid membranes, with an average single-channel conductance of 0.5 ± 0.02 nS in 1 M KCl electrolyte. Additionally, we demonstrated that SmChiP allowed the passage of small molecules with a size exclusion limit of <300 Da and exhibited substrate specificity toward chitooligosaccharides, both in membrane and detergent-solubilized forms. We found that SmChiP interacted strongly with chitopentaose (Kd = 23 ± 2.0 μM) and chitohexaose (Kd = 17 ± 0.6 μM) but did not recognize nonchitose oligosaccharides (maltohexaose and cellohexaose). Given that S. marcescens can use chitin as a primary energy source, SmChiP may serve as a target for further development of nutrient-based antimicrobial therapies directed against multidrug antibiotic-resistant S. marcescens infections.
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Affiliation(s)
- H Sasimali M Soysa
- School of Chemistry, Institute of Science, Suranaree University of Technology, Nakhon Ratchasima, Thailand
| | - Sawitree Kumsaoad
- School of Biomolecular Science and Engineering (BSE), Vidyasirimedhi Institute of Science and Technology (VISTEC), Tumbol Payupnai, Wangchan District, Rayong, Thailand 21210
| | - Rawiporn Amornloetwattana
- School of Biomolecular Science and Engineering (BSE), Vidyasirimedhi Institute of Science and Technology (VISTEC), Tumbol Payupnai, Wangchan District, Rayong, Thailand 21210
| | - Takeshi Watanabe
- Faculty of Agro-Food Science, Department of Agro-Food Science, Niigata Agro-Food University, Tainai-shi, Niigata 959-2702, Japan
| | - Wipa Suginta
- School of Biomolecular Science and Engineering (BSE), Vidyasirimedhi Institute of Science and Technology (VISTEC), Tumbol Payupnai, Wangchan District, Rayong, Thailand 21210.
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Amornloetwattana R, Robinson RC, Soysa HSM, van den Berg B, Suginta W. Chitoporin from Serratia marcescens: recombinant expression, purification and crystallization. Acta Crystallogr F Struct Biol Commun 2020; 76:536-543. [PMID: 33135672 PMCID: PMC7605108 DOI: 10.1107/s2053230x20013874] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Accepted: 10/18/2020] [Indexed: 11/10/2022] Open
Abstract
Serratia marcescens is an opportunistic pathogen that commonly causes hospital-acquired infections and can utilize chitin-enriched nutrients as an alternative energy source. This study reports the identification of a chitoporin (ChiP), termed SmChiP, from the outer membrane of S. marcescens. Sequence alignment with genetically characterized ChiPs suggests that SmChiP is more closely related to the monomeric EcChiP from Escherichia coli than to the trimeric VhChiP from Vibrio campbellii. A single crystal of SmChiP grown under the condition 22%(w/v) PEG 8000, 0.1 M calcium acetate, 0.1 M MES pH 6.0 diffracted X-ray synchrotron radiation to 1.85 Å resolution. SmChiP co-crystallized with chitohexaose under the condition 19%(w/v) PEG 1500, 2 M ammonium phosphate monobasic, 0.1 M HEPES pH 7.0 diffracted X-rays to 2.70 Å resolution. Preliminary crystallographic analysis shows that both SmChiP crystal forms contain one molecule per asymmetric unit and that they belong to the tetragonal space groups P42212 and P41212, respectively. The SmChiP crystal has unit-cell parameters a = 82.97, b = 82.97, c = 189.53 Å, α = β = γ = 90°, while the crystal of SmChiP in complex with chitohexaose has unit-cell parameters a = 73.24, b = 73.24, c = 213.46 Å, α = β = γ = 90°. Initial assessment of the complex structure clearly revealed electron density for the sugar ligand. Structure determination of SmChiP in the absence and presence of chitohexaose should reveal the molecular basis of chitin utilization by S. marcescens.
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Affiliation(s)
- Rawiporn Amornloetwattana
- School of Biomolecular Science and Engineering, Vidyasirimedhi Institute of Science and Technology, Payupnai, Wangchan, Rayong 21210, Thailand
| | - Robert C. Robinson
- School of Biomolecular Science and Engineering, Vidyasirimedhi Institute of Science and Technology, Payupnai, Wangchan, Rayong 21210, Thailand
- Research Institute for Interdisciplinary Science, Okayama University, Okayama 700-8530, Japan
| | - Hannadige Sasimali Madusanka Soysa
- Department of Physical Sciences and Technology, Faculty of Applied Sciences, Sabaragamuwa University of Sri Lanka, Belihuloya 70140, Sri Lanka
| | - Bert van den Berg
- Biosciences Institute, The Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, United Kingdom
| | - Wipa Suginta
- School of Biomolecular Science and Engineering, Vidyasirimedhi Institute of Science and Technology, Payupnai, Wangchan, Rayong 21210, Thailand
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Chitinase Expression in Listeria monocytogenes Is Influenced by lmo0327, Which Encodes an Internalin-Like Protein. Appl Environ Microbiol 2017; 83:AEM.01283-17. [PMID: 28887418 PMCID: PMC5666140 DOI: 10.1128/aem.01283-17] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Accepted: 08/23/2017] [Indexed: 02/02/2023] Open
Abstract
The chitinolytic system of Listeria monocytogenes thus far comprises two chitinases, ChiA and ChiB, and a lytic polysaccharide monooxygenase, Lmo2467. The role of the system in the bacterium appears to be pleiotropic, as besides mediating the hydrolysis of chitin, the second most ubiquitous carbohydrate in nature, the chitinases have been deemed important for the colonization of unicellular molds, as well as mammalian hosts. To identify additional components of the chitinolytic system, we screened a transposon mutant library for mutants exhibiting impaired chitin hydrolysis. The screening yielded a mutant with a transposon insertion in a locus corresponding to lmo0327 of the EGD-e strain. lmo0327 encodes a large (1,349 amino acids [aa]) cell wall-associated protein that has been proposed to possess murein hydrolase activity. The single inactivation of lmo0327, as well as of lmo0325 that codes for a putative transcriptional regulator functionally related to lmo0327, led to an almost complete abolishment of chitinolytic activity. The effect could be traced at the transcriptional level, as both chiA and chiB transcripts were dramatically decreased in the lmo0327 mutant. In accordance with that, we could barely detect ChiA and ChiB in the culture supernatants of the mutant strain. Our results provide new information regarding the function of the lmo0325-lmo0327 locus in L. monocytogenes and link it to the expression of chitinolytic activity. IMPORTANCE Many bacteria from terrestrial and marine environments express chitinase activities enabling them to utilize chitin as the sole source of carbon and nitrogen. Interestingly, several bacterial chitinases may also be involved in host pathogenesis. For example, in the important foodborne pathogen Listeria monocytogenes, the chitinases ChiA and ChiB and the lytic polysaccharide monooxygenase Lmo2467 are implicated in chitin assimilation but also act as virulence factors during the infection of mammalian hosts. Therefore, it is important to identify their regulators and induction cues to understand how the different roles of the chitinolytic system are controlled and mediated. Here, we provide evidence for the importance of lmo0327 and lmo0325, encoding a putative internalin/autolysin and a putative transcriptional activator, respectively, in the efficient expression of chitinase activity in L. monocytogenes and thereby provide new information regarding the function of the lmo0325-lmo0327 locus.
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Suzuki K, Shimizu M, Sasaki N, Ogawa C, Minami H, Sugimoto H, Watanabe T. Regulation of the chitin degradation and utilization system by the ChiX small RNA in Serratia marcescens 2170. Biosci Biotechnol Biochem 2016; 80:376-85. [DOI: 10.1080/09168451.2015.1083399] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Abstract
Serratia marcescens 2170 produces three different types of chitinases and chitin-binding protein CBP21. We found that transposon insertion into the 5′ untranslated region (5′ UTR) of chiPQ-ctb led to defective chitinase and CBP21 production. ChiX small RNA possessed the complementary sequence of the 5′ UTRs of the chiPQ-ctb and chiR and repressed the expression of chiP and chiR. ChiX was detected in a medium containing glucose, glycerol, GlcNAc, and (GlcNAc)2, but the expression of both chiP and chiR was only observed in a medium containing (GlcNAc)2. ∆chiX mutant produced chitinases, CBP21, and chitobiase without induction. chiP transcripts were more abundant than those of chiR or chiX in a medium containing (GlcNAc)2. These results suggest that the constitutively expressed ChiX binds to the highly abundant chiP 5′ UTR, thereby leading to the induction of chiR mRNA translation and the subsequent expression of chitinases and CBP21.
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Affiliation(s)
- Kazushi Suzuki
- Graduate School of Science and Technology, Niigata University, Niigata, Japan
- Faculty of Agriculture, Department of Applied Biological Chemistry, Niigata University, Niigata, Japan
| | - Mari Shimizu
- Graduate School of Science and Technology, Niigata University, Niigata, Japan
| | - Naomi Sasaki
- Graduate School of Science and Technology, Niigata University, Niigata, Japan
| | - Chisana Ogawa
- Graduate School of Science and Technology, Niigata University, Niigata, Japan
| | - Haruka Minami
- Graduate School of Science and Technology, Niigata University, Niigata, Japan
| | - Hayuki Sugimoto
- Graduate School of Science and Technology, Niigata University, Niigata, Japan
- Faculty of Agriculture, Department of Applied Biological Chemistry, Niigata University, Niigata, Japan
| | - Takeshi Watanabe
- Graduate School of Science and Technology, Niigata University, Niigata, Japan
- Faculty of Agriculture, Department of Applied Biological Chemistry, Niigata University, Niigata, Japan
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Takanao S, Honma S, Miura T, Ogawa C, Sugimoto H, Suzuki K, Watanabe T. Construction and basic characterization of deletion mutants of the genes involved in chitin utilization by Serratia marcescens 2170. Biosci Biotechnol Biochem 2014; 78:524-32. [DOI: 10.1080/09168451.2014.882755] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Abstract
In order to elucidate the roles of ChiP, ChiQ, and ChiX in chitin utilization by Serratia marcescens 2170, the construction of single-gene deletion mutants of the chiP, chiQ, and chiX genes was attempted by allelic exchange mutagenesis. ΔchiP formed smaller clearing zones and ΔchiX formed larger ones than wild-type 2170 on an agar plate containing colloidal chitin. ΔchiP grew slowly on the lower concentration of (GlcNAc)2, and there was essentially no growth on chitin oligosaccharides larger than (GlcNAc)3. The gene product of chiP was detected in the outer membrane fraction, consistently with the hypothesis that chiP encodes outer membrane chitoporin. Deletion of chiQ decreased and that of chiX increased the growth rates on chitin oligosaccharides. These observations strongly suggest that all three genes are involved in chitin utilization and that the deletion mutants obtained in this study might prove useful tools to clarify the details of the chitin utilization system of this bacterium.
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Affiliation(s)
- Shinya Takanao
- Graduate School of Science and Technology, Niigata University, Niigata, Japan
| | - Syouta Honma
- Graduate School of Science and Technology, Niigata University, Niigata, Japan
| | - Takuma Miura
- Graduate School of Science and Technology, Niigata University, Niigata, Japan
| | - Chisana Ogawa
- Graduate School of Science and Technology, Niigata University, Niigata, Japan
| | - Hayuki Sugimoto
- Graduate School of Science and Technology, Niigata University, Niigata, Japan
- Faculty of Agriculture, Department of Applied Biological Chemistry, Niigata University, Niigata, Japan
| | - Kazushi Suzuki
- Graduate School of Science and Technology, Niigata University, Niigata, Japan
- Faculty of Agriculture, Department of Applied Biological Chemistry, Niigata University, Niigata, Japan
| | - Takeshi Watanabe
- Graduate School of Science and Technology, Niigata University, Niigata, Japan
- Faculty of Agriculture, Department of Applied Biological Chemistry, Niigata University, Niigata, Japan
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