1gnz

LECTIN I-B4 FROM GRIFFONIA SIMPLICIFOLIA (GS I-B4)METAL FREE FORM

spinqualitylabelsall models 1gnz, resolution 2.50Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1gnz is a 1 chain structure with sequence from Griffonia simplicifolia. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.5Å Ligands: NAG, PO4 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function Q8W1R6_GRISI Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed Seeds from the African legume shrub Griffonia simplicifolia contain several lectins. Among them the tetrameric lectin GS I-B(4) has strict specificity for terminal alpha Gal residues, whereas the closely related lectin GS I-A(4) can also bind to alpha GalNAc. These two lectins are commonly used as markers in histology or for research in xenotransplantation. To elucidate the basis for the fine difference in specificity, the amino acid sequences of both lectins have been determined and show 89% identity. The crystal structure of GS I-B(4), determined at 2.5-A resolution, reveals a new quaternary structure that has never been observed in other legume lectins. An unexpected loss of both Ca(2+) and Mn(2+) ions, which are necessary for carbohydrate binding in legume lectins, may be related to a particular amino acid sequence Pro-Glu-Pro in the metal binding loop. Comparison with demetallized concanavalin A reveals a different process for the loss of metal ions and for the subsequent loss of carbohydrate binding activity. The GS I-A x alpha GalNAc and GS I-B x alpha Gal complexes were constructed using homology modeling and docking approaches. The unusual presence of an aromatic amino acid at position 47 (Tyr in I-A and Trp in I-B) explains the strong preference for alpha-anomeric sugars in both isolectins. Alteration at one amino acid position, Ala(106) in I-A versus Glu(106) in I-B, is the basis for the observed specificities toward alpha GalNAc and alpha Gal. Isolectins I-A and I-B of Griffonia (Bandeiraea) simplicifolia. Crystal structure of metal-free GS I-B(4) and molecular basis for metal binding and monosaccharide specificity.,Lescar J, Loris R, Mitchell E, Gautier C, Chazalet V, Cox V, Wyns L, Perez S, Breton C, Imberty A J Biol Chem. 2002 Feb 22;277(8):6608-14. Epub 2001 Nov 19. PMID:11714720 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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