This protein family, mainly found in Bacteroides, includes the putative surface glycan binding protein (SGBP) BT4661 from Bacteroides thetaiotaomicron (Swiss:Q89YS0). BT4661 appears to play a role in the bacterial degrading apparatus of the host glycosaminoglycans heparin (Hep) and heparan sulfate (HS). It shows six discrete domains that adopt an Ig-like fold arranged in an extended, curved conformation [1].

1: How members of the human gut microbiota overcome the sulfation problem posed by glycosaminoglycans. Cartmell A, Lowe EC, Basle A, Firbank SJ, Ndeh DA, Murray H, Terrapon N, Lombard V, Henrissat B, Turnbull JE, Czjzek M, Gilbert HJ, Bolam DN; Proc Natl Acad Sci U S A. 2017;114:7037-7042. PMID:28630303