Enigmatic Pilus-Like Endospore Appendages of <i>Bacillus cereus</i> Group Species
The endospores (spores) of many <i>Bacillus cereus</i> sensu lato species are decorated with multiple hair/pilus-like appendages. Although they have been observed for more than 50 years, all efforts to characterize these fibers in detail have failed until now, largely due to their extrao...
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MDPI AG
2021-11-01
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| Series: | International Journal of Molecular Sciences |
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| Online Access: | https://www.mdpi.com/1422-0067/22/22/12367 |
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| author | Ephrem Debebe Zegeye Brajabandhu Pradhan Ann-Katrin Llarena Marina Aspholm |
| author_facet | Ephrem Debebe Zegeye Brajabandhu Pradhan Ann-Katrin Llarena Marina Aspholm |
| author_sort | Ephrem Debebe Zegeye |
| collection | DOAJ |
| description | The endospores (spores) of many <i>Bacillus cereus</i> sensu lato species are decorated with multiple hair/pilus-like appendages. Although they have been observed for more than 50 years, all efforts to characterize these fibers in detail have failed until now, largely due to their extraordinary resilience to proteolytic digestion and chemical solubilization. A recent structural analysis of <i>B. cereus</i> endospore appendages (Enas) using cryo-electron microscopy has revealed the structure of two distinct fiber morphologies: the longer and more abundant “Staggered-type” (S-Ena) and the shorter “Ladder-like” type (L-Ena), which further enabled the identification of the genes encoding the S-Ena. Ena homologs are widely and uniquely distributed among <i>B. cereus</i> sensu lato species, suggesting that appendages play important functional roles in these species. The discovery of <i>ena</i> genes is expected to facilitate functional studies involving Ena-depleted mutant spores to explore the role of Enas in the interaction between spores and their environment. Given the importance of <i>B. cereus</i> spores for the food industry and in medicine, there is a need for a better understanding of their biological functions and physicochemical properties. In this review, we discuss the current understanding of the Ena structure and the potential roles these remarkable fibers may play in the adhesion of spores to biotic and abiotic surfaces, aggregation, and biofilm formation. |
| first_indexed | 2024-03-10T05:25:36Z |
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| issn | 1661-6596 1422-0067 |
| language | English |
| last_indexed | 2024-03-10T05:25:36Z |
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| series | International Journal of Molecular Sciences |
| spelling | doaj.art-5e887c1cc0bb461a805c17344e71d2eb2023-11-22T23:41:11ZengMDPI AGInternational Journal of Molecular Sciences1661-65961422-00672021-11-0122221236710.3390/ijms222212367Enigmatic Pilus-Like Endospore Appendages of <i>Bacillus cereus</i> Group SpeciesEphrem Debebe Zegeye0Brajabandhu Pradhan1Ann-Katrin Llarena2Marina Aspholm3Department of Paraclinical Sciences, Faculty of Veterinary Medicine, Norwegian University of Life Sciences (NMBU), P.O. Box 5003, 1432 Ås, NorwayStructural and Molecular Microbiology, VIB-VUB Center for Structural Biology, VIB, 1050 Brussels, BelgiumDepartment of Paraclinical Sciences, Faculty of Veterinary Medicine, Norwegian University of Life Sciences (NMBU), P.O. Box 5003, 1432 Ås, NorwayDepartment of Paraclinical Sciences, Faculty of Veterinary Medicine, Norwegian University of Life Sciences (NMBU), P.O. Box 5003, 1432 Ås, NorwayThe endospores (spores) of many <i>Bacillus cereus</i> sensu lato species are decorated with multiple hair/pilus-like appendages. Although they have been observed for more than 50 years, all efforts to characterize these fibers in detail have failed until now, largely due to their extraordinary resilience to proteolytic digestion and chemical solubilization. A recent structural analysis of <i>B. cereus</i> endospore appendages (Enas) using cryo-electron microscopy has revealed the structure of two distinct fiber morphologies: the longer and more abundant “Staggered-type” (S-Ena) and the shorter “Ladder-like” type (L-Ena), which further enabled the identification of the genes encoding the S-Ena. Ena homologs are widely and uniquely distributed among <i>B. cereus</i> sensu lato species, suggesting that appendages play important functional roles in these species. The discovery of <i>ena</i> genes is expected to facilitate functional studies involving Ena-depleted mutant spores to explore the role of Enas in the interaction between spores and their environment. Given the importance of <i>B. cereus</i> spores for the food industry and in medicine, there is a need for a better understanding of their biological functions and physicochemical properties. In this review, we discuss the current understanding of the Ena structure and the potential roles these remarkable fibers may play in the adhesion of spores to biotic and abiotic surfaces, aggregation, and biofilm formation.https://www.mdpi.com/1422-0067/22/22/12367endosporesporepiliappendage<i>Bacillus cereus</i>Ena |
| spellingShingle | Ephrem Debebe Zegeye Brajabandhu Pradhan Ann-Katrin Llarena Marina Aspholm Enigmatic Pilus-Like Endospore Appendages of <i>Bacillus cereus</i> Group Species International Journal of Molecular Sciences endospore spore pili appendage <i>Bacillus cereus</i> Ena |
| title | Enigmatic Pilus-Like Endospore Appendages of <i>Bacillus cereus</i> Group Species |
| title_full | Enigmatic Pilus-Like Endospore Appendages of <i>Bacillus cereus</i> Group Species |
| title_fullStr | Enigmatic Pilus-Like Endospore Appendages of <i>Bacillus cereus</i> Group Species |
| title_full_unstemmed | Enigmatic Pilus-Like Endospore Appendages of <i>Bacillus cereus</i> Group Species |
| title_short | Enigmatic Pilus-Like Endospore Appendages of <i>Bacillus cereus</i> Group Species |
| title_sort | enigmatic pilus like endospore appendages of i bacillus cereus i group species |
| topic | endospore spore pili appendage <i>Bacillus cereus</i> Ena |
| url | https://www.mdpi.com/1422-0067/22/22/12367 |
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