6x3q
Hsa Siglec and Unique domains in complex with 3'sialyl-N-acetyllactosamine trisaccharide
Structural highlights
FunctionHSA_STRGC A cell wall protein involved with PadA in host cell interactions required for colonization and pathogensis (Probable) (PubMed:19884334, PubMed:27616700). Mediates hemagglutination and adherence to ghst glycoproteins (PubMed:11854202). Recognizes fetuin-A (AHSG), a highly glycosylated human plasma protein, also involved in recognition of human platelets, probably via platelet glycoprotein Ib alpha (GP1BA) (PubMed:19884334). Acts in concert with PadA to promote binding to glycosylated human fibronectin (FN1) and vitronectin (VTN), and biofilm formation. Plays a major role in fibronectin and vitronectin binding; binding is mediated by glycosylated regions. Probably mediates interaction of PadA with resting platelets (PubMed:27616700).[1] [2] [3] [4] Publication Abstract from PubMedBacterial binding to host receptors underlies both commensalism and pathogenesis. Many streptococci adhere to protein-attached carbohydrates expressed on cell surfaces using Siglec-like binding regions (SLBRs). The precise glycan repertoire recognized may dictate whether the organism is a strict commensal versus a pathogen. However, it is currently not clear what drives receptor selectivity. Here, we use five representative SLBRs and identify regions of the receptor binding site that are hypervariable in sequence and structure. We show that these regions control the identity of the preferred carbohydrate ligand using chimeragenesis and single amino acid substitutions. We further evaluate how the identity of the preferred ligand affects the interaction with glycoprotein receptors in human saliva and plasma samples. As point mutations can change the preferred human receptor, these studies suggest how streptococci may adapt to changes in the environmental glycan repertoire. Origins of glycan selectivity in streptococcal Siglec-like adhesins suggest mechanisms of receptor adaptation.,Bensing BA, Stubbs HE, Agarwal R, Yamakawa I, Luong K, Solakyildirim K, Yu H, Hadadianpour A, Castro MA, Fialkowski KP, Morrison KM, Wawrzak Z, Chen X, Lebrilla CB, Baudry J, Smith JC, Sullam PM, Iverson TM Nat Commun. 2022 May 18;13(1):2753. doi: 10.1038/s41467-022-30509-y. PMID:35585145[5] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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