| Structural highlights
Function
CGEA_BACSU Involved in the formation of the spore crust, the outermost layer of the spore (PubMed:21665972, PubMed:31502725, PubMed:37485949). Plays a role in crust glycosylation (PubMed:31502725, PubMed:37485949). Required to initiate spore polysaccharides (SPS) assembly and serves as an anchor protein linking the crust and SPS layers (PubMed:37485949).[1] [2] [3]
Publication Abstract from PubMed
The Bacillus subtilis spore crust is an exceptionally robust proteinaceous layer that protects spores under extreme environmental conditions. Among its key components, CgeA, a glycosylation-associated protein, plays a critical role in modifying crust properties through its glycosylated moiety, enhancing spore dispersal in aqueous environments. In this study, we present the high-resolution cryo-electron microscopy structure of the core region of CgeA at 3.05 A resolution, revealing a doughnut-like hexameric assembly. The N-terminal regions are disordered, whereas the C-terminal region forms the core of the hexamer. Although the loop containing Thr112 was not resolved in the density map, its location can be inferred from surrounding residues, suggesting that Thr112 is situated on the exposed surface of the hexamer. On the opposite face, a distinct electrostatic pattern is observed, featuring a negatively charged central pore and a positively charged outer surface. Modeling and biochemical studies with the putative glycosyltransferase CgeB provide insights into how the glycosyl group is transferred to Thr112. This study offers a molecular-level understanding of the assembly, glycosylation, and environmental adaptability of the B. subtilis spore crust, with valuable implications for controlling spore formation in industrial applications.
Cryo-EM structure of the glycosylated protein CgeA in the crust of Bacillus subtilis endospores.,Park M, Kim D, Baek Y, Jo E, Hyun J, Ha NC J Microbiol. 2025 Oct;63(10):e2504013. doi: 10.71150/jm.2504013. Epub 2025 Oct , 31. PMID:41164959[4]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Imamura D, Kuwana R, Takamatsu H, Watabe K. Proteins involved in formation of the outermost layer of Bacillus subtilis spores. J Bacteriol. 2011 Aug;193(16):4075-80. PMID:21665972 doi:10.1128/JB.05310-11
- ↑ Bartels J, Blüher A, López Castellanos S, Richter M, Günther M, Mascher T. The Bacillus subtilis endospore crust: protein interaction network, architecture and glycosylation state of a potential glycoprotein layer. Mol Microbiol. 2019 Nov;112(5):1576-1592. PMID:31502725 doi:10.1111/mmi.14381
- ↑ Nakaya Y, Uchiike M, Hattori M, Moriyama M, Abe K, Kim E, Eichenberger P, Imamura D, Sato T. Identification of CgeA as a glycoprotein that anchors polysaccharides to the spore surface in Bacillus subtilis. Mol Microbiol. 2023 Sep;120(3):384-396. PMID:37485949 doi:10.1111/mmi.15126
- ↑ Park M, Kim D, Baek Y, Jo E, Hyun J, Ha NC. Cryo-EM structure of the glycosylated protein CgeA in the crust of Bacillus subtilis endospores. J Microbiol. 2025 Oct;63(10):e2504013. PMID:41164959 doi:10.71150/jm.2504013
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