Structural Basis of the Carbohydrate Specificities of Jacalin: An X-ray and Modeling StudyJeyaprakash, A.A., Katiyar, S., Swaminathan, C.P., Sekar, K., Surolia, A., Vijayan, M.
(2003) J.MOL.BIOL. 332: 217-228
- PubMed: 12946359
- Primary Citation of Related Structures:
- Also Cited By: 4R6R, 4R6Q, 4R6P, 4R6O, 4R6N, 1WS5, 1WS4, 1VBP, 1VBO
- PubMed Abstract:
- Crystal structure of the jacalin-T-antigen complex and a comparative study of lectin-T-antigen complexes
Jeyaprakash, A.A.,Rani, P.G.,Reddy, G.B.,Banumathi, S.,Betzel, C.,Sekar, K.,Surolia, A.,Vijayan, M.
(2002) J.Mol.Biol. 321: 637
- A novel mode of carbohydrate recognition in jacalin, a Moraceae plant lectin with a beta-prism fold
Sankaranarayanan, R.,sekar, K.,Banerjee, R.,Sharma, V.,Surolia, A.,Vijayan, M.
(1996) Nat.Struct.Mol.Biol. 3: 596
The structures of the complexes of tetrameric jacalin with Gal, Me-alpha-GalNAc, Me-alpha-T-antigen, GalNAcbeta1-3Gal-alpha-O-Me and Galalpha1-6Glc (mellibiose) show that the sugar-binding site of jacalin has three components: the primary site, secon ...
The structures of the complexes of tetrameric jacalin with Gal, Me-alpha-GalNAc, Me-alpha-T-antigen, GalNAcbeta1-3Gal-alpha-O-Me and Galalpha1-6Glc (mellibiose) show that the sugar-binding site of jacalin has three components: the primary site, secondary site A, and secondary site B. In these structures and in the two structures reported earlier, Gal or GalNAc occupy the primary site with the anomeric carbon pointing towards secondary site A. The alpha-substituents, when present, interact, primarily hydrophobically, with secondary site A which has variable geometry. O-H..., centered pi and C-H...pi hydrogen bonds involving this site also exist. On the other hand, beta-substitution leads to severe steric clashes. Therefore, in complexes involving beta-linked disaccharides, the reducing sugar binds at the primary site with the non-reducing end located at secondary site B. The interactions at secondary site B are primarily through water bridges. Thus, the nature of the linkage determines the mode of the association of the sugar with jacalin. The interactions observed in the crystal structures and modeling based on them provide a satisfactory qualitative explanation of the available thermodynamic data on jacalin-carbohydrate interactions. They also lead to fresh insights into the nature of the binding of glycoproteins by jacalin.
Molecular Biophysics Unit, UGC Centre of Advanced Study, Indian Institute of Science, Bangalore 560 012, India.