2ya0
Catalytic Module of the Multi-modular glycogen-degrading pneumococcal virulence factor SpuA
Structural highlights
FunctionPULA_STRPN Virulence factor (By similarity). Involved in the degradation of glycogen of the mammalian host cells (PubMed:21565699). Hydrolyzes the alpha-1,6-branchpoints of glycogen (PubMed:20497336, PubMed:21565699). Hydrolyzes pullulan. Does not hydrolyze dextran (PubMed:20497336). Binds to mouse lung alveolar type II cells that are rich in glycogen stores. Is an alpha-glucan-specific carbohydrate-binding protein, which binds to amylose (pure alpha-(1,4)-linked glucose), amylopectin (alpha-(1,4)-linked glucose with alpha-(1,6) branch points), pullulan (linear polymer of mixed alpha-(1,4)- and alpha-(1,6)-linked glucose) and glycogen (similar to amylopectin with more frequent alpha-(1,6) branch points) in vitro. Does not bind to dextran (a linear polymer of alpha-(1,6)-linked glucose) (PubMed:17187076).[UniProtKB:A0A0H2ZL64][1] [2] [3] Publication Abstract from PubMedSpuA is a large multimodular cell wall-attached enzyme involved in the degradation of glycogen by the pathogenic bacterium Streptococcus pneumoniae. The deletion of the gene encoding SpuA from the bacterium resulted in a strain with reduced competitiveness in a mouse model of virulence relative to the parent strain, linking the degradation of host-glycogen to the virulence of the bacterium. Through the combined use of X-ray crystallography, small-angle X-ray scattering, and inhibitor binding, the molecular features involved in substrate recognition by this complex protein are revealed. This uniquely illustrates the complexity of the active site, the conformational changes incurred during carbohydrate binding by this protein, and the interaction and cooperation of its composite modules during this process. New insight into the function of this particular pneumococcal virulence factor is provided along with substantial contributions to the nascent framework for understanding the structural and functional interplay between modules in multimodular carbohydrate-active enzymes. The conformation and function of a multimodular glycogen-degrading pneumococcal virulence factor.,Lammerts van Bueren A, Ficko-Blean E, Pluvinage B, Hehemann JH, Higgins MA, Deng L, Ogunniyi AD, Stroeher UH, El Warry N, Burke RD, Czjzek M, Paton JC, Vocadlo DJ, Boraston AB Structure. 2011 May 11;19(5):640-51. PMID:21565699[4] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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