CesH Represses Cereulide Synthesis as an Alpha/Beta Fold Hydrolase in <i>Bacillus cereus</i>
Cereulide is notorious as a heat-stable emetic toxin produced by <i>Bacillus cereus</i> and glucose is supposed to be an ingredient supporting its formation. This study showed that glucose addition benefited on cell growth and the early transcription of genes involved in substrate accumu...
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| Format: | Article |
| Language: | English |
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MDPI AG
2019-04-01
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| Series: | Toxins |
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| Online Access: | https://www.mdpi.com/2072-6651/11/4/231 |
| _version_ | 1798006713957220352 |
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| author | Shen Tian Hairong Xiong Peiling Geng Zhiming Yuan Xiaomin Hu |
| author_facet | Shen Tian Hairong Xiong Peiling Geng Zhiming Yuan Xiaomin Hu |
| author_sort | Shen Tian |
| collection | DOAJ |
| description | Cereulide is notorious as a heat-stable emetic toxin produced by <i>Bacillus cereus</i> and glucose is supposed to be an ingredient supporting its formation. This study showed that glucose addition benefited on cell growth and the early transcription of genes involved in substrate accumulation and toxin synthesis, but it played a negative role in the final production of cereulide. Meanwhile, a lasting enhancement of <i>cesH</i> transcription was observed with the addition of glucose. Moreover, the cereulide production in Δ<i>cesH</i> was obviously higher than that in the wild type. This indicates that CesH has a repression effect on cereulide production. Bioinformatics analysis revealed that CesH was an alpha/beta hydrolase that probably associated with the cell membrane, which was verified by subcellular localization. The esterase activity against para-nitrophenyl acetate (PNPC2) of the recombinant CesH was confirmed. Although no sign of ester bond cleavage in cereulide or valinomycin was demonstrated in in vitro assays, CesH could reverse the cereulide analogue sensitivity of <i>Bacillus subtilis</i> in vivo, by which toxin degradation was facilitated. Moreover, site directed mutations identified that the conserved catalytic triad of CesH might consist of Serine 86, Glutamate 199, and Histidine 227. These results help us to understand the regulation of cereulide production and provide clues for developing control measurements. |
| first_indexed | 2024-04-11T12:58:58Z |
| format | Article |
| id | doaj.art-0d247766781b47dc9723f87ed4f2766b |
| institution | Directory Open Access Journal |
| issn | 2072-6651 |
| language | English |
| last_indexed | 2024-04-11T12:58:58Z |
| publishDate | 2019-04-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Toxins |
| spelling | doaj.art-0d247766781b47dc9723f87ed4f2766b2022-12-22T04:22:59ZengMDPI AGToxins2072-66512019-04-0111423110.3390/toxins11040231toxins11040231CesH Represses Cereulide Synthesis as an Alpha/Beta Fold Hydrolase in <i>Bacillus cereus</i>Shen Tian0Hairong Xiong1Peiling Geng2Zhiming Yuan3Xiaomin Hu4Key Laboratory of Special Pathogens and Biosafety, Center for Emerging Infectious Diseases, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, ChinaCollege of Life Science, South-Central University for Nationalities, Wuhan 430074, ChinaKey Laboratory of Special Pathogens and Biosafety, Center for Emerging Infectious Diseases, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, ChinaKey Laboratory of Special Pathogens and Biosafety, Center for Emerging Infectious Diseases, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, ChinaKey Laboratory of Special Pathogens and Biosafety, Center for Emerging Infectious Diseases, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, ChinaCereulide is notorious as a heat-stable emetic toxin produced by <i>Bacillus cereus</i> and glucose is supposed to be an ingredient supporting its formation. This study showed that glucose addition benefited on cell growth and the early transcription of genes involved in substrate accumulation and toxin synthesis, but it played a negative role in the final production of cereulide. Meanwhile, a lasting enhancement of <i>cesH</i> transcription was observed with the addition of glucose. Moreover, the cereulide production in Δ<i>cesH</i> was obviously higher than that in the wild type. This indicates that CesH has a repression effect on cereulide production. Bioinformatics analysis revealed that CesH was an alpha/beta hydrolase that probably associated with the cell membrane, which was verified by subcellular localization. The esterase activity against para-nitrophenyl acetate (PNPC2) of the recombinant CesH was confirmed. Although no sign of ester bond cleavage in cereulide or valinomycin was demonstrated in in vitro assays, CesH could reverse the cereulide analogue sensitivity of <i>Bacillus subtilis</i> in vivo, by which toxin degradation was facilitated. Moreover, site directed mutations identified that the conserved catalytic triad of CesH might consist of Serine 86, Glutamate 199, and Histidine 227. These results help us to understand the regulation of cereulide production and provide clues for developing control measurements.https://www.mdpi.com/2072-6651/11/4/231<i>Bacillus cereus</i>cereulidecesHalpha/beta hydrolase |
| spellingShingle | Shen Tian Hairong Xiong Peiling Geng Zhiming Yuan Xiaomin Hu CesH Represses Cereulide Synthesis as an Alpha/Beta Fold Hydrolase in <i>Bacillus cereus</i> Toxins <i>Bacillus cereus</i> cereulide cesH alpha/beta hydrolase |
| title | CesH Represses Cereulide Synthesis as an Alpha/Beta Fold Hydrolase in <i>Bacillus cereus</i> |
| title_full | CesH Represses Cereulide Synthesis as an Alpha/Beta Fold Hydrolase in <i>Bacillus cereus</i> |
| title_fullStr | CesH Represses Cereulide Synthesis as an Alpha/Beta Fold Hydrolase in <i>Bacillus cereus</i> |
| title_full_unstemmed | CesH Represses Cereulide Synthesis as an Alpha/Beta Fold Hydrolase in <i>Bacillus cereus</i> |
| title_short | CesH Represses Cereulide Synthesis as an Alpha/Beta Fold Hydrolase in <i>Bacillus cereus</i> |
| title_sort | cesh represses cereulide synthesis as an alpha beta fold hydrolase in i bacillus cereus i |
| topic | <i>Bacillus cereus</i> cereulide cesH alpha/beta hydrolase |
| url | https://www.mdpi.com/2072-6651/11/4/231 |
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