ricin B-type lectin domain, beta-trefoil fold, found in Macrolepiota procera ricin B-like lectin (MPL), Clitocybe nebularis lectin (CNL), and similar proteins
MPL and CNL are a homodimeric ricin B-like lectins with a beta-trefoil fold that is characterized by 12 beta strands folded into three similar trefoil subdomains (alpha, beta, and gamma) associated to give an overall structure with pseudo-3-fold symmetry. Their alpha subunit may harbor a sugar-binding pocket. MPL has the highest specificity for terminal N-acetyllactosamine and other beta-galactosides. CNL induces maturation and activation of dendritic cells via the toll-like receptor 4 pathway. It is specific for terminal, non-reducing N-acetylgalactosamine (Gal-NAc)-containing carbohydrates including N,N'-diacetyllactosediamine/LDN (GalNAcbeta1-4GlcNAc, LacdiNAc). It is also specific for carbohydrates containing N-acetylglucosamine (-GlcNAc) or N-acetyllactosamine (-Galbeta1-4GlcNAc) at the reducing end.
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