1FX5

CRYSTAL STRUCTURE ANALYSIS OF ULEX EUROPAEUS LECTIN I

Summary for 1FX5

• Entry DOI: 10.2210/pdb1fx5/pdb
• Descriptor: ANTI-H(O) LECTIN I, Xylitol-(1-2)-[alpha-D-mannopyranose-(1-3)][alpha-D-mannopyranose-(1-6)]beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-[alpha-L-fucopyranose-(1-3)]2-acetamido-2-deoxy-beta-D-glucopyranose, alpha-L-fucopyranose-(1-3)-[2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)]2-acetamido-2-deoxy-beta-D-glucopyranose, ... (7 entities in total)
• Functional Keywords: legume lectin, ue-i, homo-dimer, fucose specific lectin, sugar binding protein
• Biological source: Ulex europaeus (furze)
• Total number of polymer chains: 2
• Total formula weight: 56017.55

Authors

Audette, G.F.,Vandonselaar, M.,Delbaere, L.T.J. (deposition date: 2000-09-25, release date: 2001-01-17, Last modification date: 2024-11-13)

Primary citation

Audette, G.F.,Vandonselaar, M.,Delbaere, L.T.
The 2.2 A resolution structure of the O(H) blood-group-specific lectin I from Ulex europaeus.
J.Mol.Biol., 304:423-433, 2000

PubMed Abstract: The tertiary and quaternary structure of the lectin I from Ulex europaeus (UE-I) has been determined to 2.2 A resolution. UE-I is a dimeric metalloglycoprotein that binds the H-type 2 human blood group determinant [alpha-L-Fucalpha(1-->2)-beta-D-Galbeta(1-->4)-beta-D-Glc NAcalpha-]. Nine changes from the published amino acid sequence were necessary to account for the electron density. The quaternary structural organization of UE-I is that of the most commonly occurring legume lectin dimer. The tertiary structure of the monomeric subunits is similar to that in the conventional lectin subunit; however, some structural differences are noted. These differences include a four-stranded anti-parallel "S" sheet in UE-I versus the five-stranded S sheet in other lectin monomers. The Ala residue of the Ala-Asp cis-peptide bond present in the carbohydrate-binding site of the conventional lectin monomer is replaced with a Thr in the UE-I structure. Also, a novel disulfide bridge linking Cys115 and Cys150 is present. There are two metallic ions, one calcium and the other manganese, per subunit. N-linked oligosaccharides are at residues 23 and 111 of each subunit. One molecule of R-2-methyl-2, 4-pentanediol (R-MPD) is present in a shallow depression on the surface of each subunit. In order to examine the binding of the H-type 2 blood group determinant by UE-I, its beta-methyl glycoside (H-type 2-OMe) was docked into the binding site of R-MPD. The epitope previously identified for H-type 2-OMe by chemical mapping proved, with only minor adjustment of amino acid residues, to be complementary to the shallow cavity occupied by R-MPD in the structure. Several key interactions have been proposed between the H-type 2-OMe and UE-I.

PubMed: 11090284
DOI: 10.1006/jmbi.2000.4214

Experimental method

X-RAY DIFFRACTION (2.2 Å)