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From Proteopedia
X-ray structure of the N-terminal domain of the flocculin Flo5 from Saccharomyces cerevisiae in complex with calcium and a1,2-mannobiose
Structural highlights
FunctionFLO5_YEAST Cell wall protein that participates directly in adhesive cell-cell interactions during yeast flocculation, a reversible, asexual and Ca(2+)-dependent process in which cells adhere to form aggregates (flocs) consisting of thousands of cells. The lectin-like protein sticks out of the cell wall of flocculent cells and selectively binds mannose residues in the cell walls of adjacent cells. Activity is inhibited by mannose, but not by glucose, maltose, sucrose or galactose. Publication Abstract from PubMedIn the budding yeast Saccharomyces cerevisiae, self-recognition and the thereby promoted aggregation of thousands of cells into protective flocs is mediated by a family of cell-surface adhesins, the flocculins (Flo). Based on this social behavior FLO genes fulfill the definition of "greenbeard" genes, which direct cooperation toward other carriers of the same gene. The process of flocculation plays an eminent role in the food industry for the production of beer and wine. However, the precise mode of flocculin-mediated surface recognition and the exact structure of cognate ligands have remained elusive. Here, we present structures of the adhesion domain of a flocculin complexed to its cognate ligands derived from yeast high-mannose oligosaccharides at resolutions up to 0.95 A. Besides a PA14-like architecture, the Flo5A domain reveals a previously undescribed lectin fold that utilizes a unique DcisD calcium-binding motif for carbohydrate binding and that is widely spread among pro- and eukaryotes. Given the high abundance of high-mannose oligosaccharides in yeast cell walls, the Flo5A structure suggests a model for recognition, where social non-self- instead of unsocial self-interactions are favored. Structural basis of flocculin-mediated social behavior in yeast.,Veelders M, Bruckner S, Ott D, Unverzagt C, Mosch HU, Essen LO Proc Natl Acad Sci U S A. 2010 Dec 28;107(52):22511-6. Epub 2010 Dec 13. PMID:21149680[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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