Holkenbrink, C., Hoiczyk, E., Kahnt, J. et al. (1 more author) (2014) Synthesis and Assembly of a Novel Glycan Layer in Myxococcus xanthus Spores. Journal of Biological Chemistry, 289 (46). pp. 32364-32378. ISSN 0021-9258
Abstract
Myxococcus xanthus is a Gram-negative deltaproteobacterium that has evolved the ability to differentiate into metabolically quiescent spores that are resistant to heat and desiccation. An essential feature of the differentiation processes is the assembly of a rigid, cell wall-like spore coat on the surface of the outer membrane. In this study, we characterize the spore coat composition and describe the machinery necessary for secretion of spore coat material and its subsequent assembly into a stress-bearing matrix. Chemical analyses of isolated spore coat material indicate that the spore coat consists primarily of short 1–4- and 1–3-linked GalNAc polymers that lack significant glycosidic branching and may be connected by glycine peptides. We show that 1–4-linked glucose (Glc) is likely a minor component of the spore coat with the majority of the Glc arising from contamination with extracellular polysaccharides, O-antigen, or storage compounds. Neither of these structures is required for the formation of resistant spores. Our analyses indicate the GalNAc/Glc polymer and glycine are exported by the ExoA-I system, a Wzy-like polysaccharide synthesis and export machinery. Arrangement of the capsular-like polysaccharides into a rigid spore coat requires the NfsA–H proteins, members of which reside in either the cytoplasmic membrane (NfsD, -E, and -G) or outer membrane (NfsA, -B, and -C). The Nfs proteins function together to modulate the chain length of the surface polysaccharides, which is apparently necessary for their assembly into a stress-bearing matrix.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2014 American Society for Biochemistry and Molecular Biology. Reproduced in accordance with the publisher's self-archiving policy. |
Keywords: | Gram-negative Bacteria; Membrane Protein; Peptidoglycan; Polysaccharide; Sporulation |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Science (Sheffield) > School of Biosciences (Sheffield) > Department of Molecular Biology and Biotechnology (Sheffield) |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 12 May 2016 11:02 |
Last Modified: | 15 May 2016 04:31 |
Published Version: | https://dx.doi.org/10.1074/jbc.M114.595504 |
Status: | Published |
Publisher: | American Society for Biochemistry and Molecular Biology |
Refereed: | Yes |
Identification Number: | 10.1074/jbc.M114.595504 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:98268 |