LG/LNS domains: multiple functions – one business end?

• Published in: Trends in biochemical sciences (Amsterdam. Regular ed.) 2001-06, Vol.26 (6), p.363-368
• Main Authors: Rudenko, Gabby, Hohenester, Erhard, Muller, Yves A
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Binding Sites; jelly-roll; Laminin - chemistry; Laminin - metabolism; Laminin G-like domain; legume lectin fold; LNS domain; Models, Molecular; Molecular Sequence Data; neurexin; Protein Conformation; Sequence Homology, Amino Acid; sex hormone-binding globulin
• ISSN: 0968-0004; 1362-4326
• DOI: 10.1016/S0968-0004(01)01832-1

The three-dimensional structures of LG/LNS domains from neurexin, the laminin α2 chain and sex hormone-binding globulin reveal a close structural relationship to the carbohydrate-binding pentraxins and other lectins. However, these LG/LNS domains appear to have a preferential ligand-interaction site distinct from the carbohydrate-binding sites found in lectins, and this interaction site accommodates not only sugars but also steroids and proteins. In fact, the LG/LNS domain interaction site has features reminiscent of the antigen-combining sites in immunoglobulins. The LG/LNS domain presents an interesting case in which the fold has remained conserved but the functional sites have evolved; consequently, making predictions of structure–function relationships on the basis of the lectin fold alone is difficult.