Structural characterisation of the native fetuin-binding protein Scilla campanulata agglutinin: a novel two-domain lectin.
The three-dimensional structure of a 244-residue, multivalent, fetuin-binding lectin, SCAfet, isolated from bluebell (Scilla campanulata) bulbs, has been solved at 3.3 A resolution by molecular replacement using the coordinates of the 119-residue, mannose-binding lectin, SCAman, also from bluebell bulbs. Unlike most monocot mannose-binding lectins, such as Galanthus nivalis agglutinin from snowdrop bulbs, which fold into a single domain, SCAfet contains two domains with approximately 55% sequence identity, joined by a linker peptide. Both domains are made up of a 12-stranded beta-prism II fold, with three putative carbohydrate-binding sites, one on each subdomain. SCAfet binds to the complex saccharides of various animal glycoproteins but not to simple sugars.
Wright
L M
LM
School of Biomolecular Sciences, Max Perutz Building, Liverpool John Moores University, Liverpool, UK.
Reynolds
C D
CD
Rizkallah
P J
PJ
Allen
A K
AK
Van Damme
E J
EJ
Donovan
M J
MJ
Peumans
W J
WJ
D000595:Amino Acid Sequence; D001665:Binding Sites; D001667:Binding, Competitive; D002352:Carrier Proteins / Q000737:chemistry*; D018360:Crystallography, X-Ray; D019281:Dimerization; D004912:Erythrocytes / Q000378:metabolism; D027801:Galanthus; D037102:Lectins / Q000737:chemistry* / Q000378:metabolism; D019668:Liliaceae / Q000737:chemistry*; D008358:Mannose / Q000378:metabolism; D037241:Mannose-Binding Lectins; D008958:Models, Molecular; D008969:Molecular Sequence Data; D037121:Plant Lectins; D017510:Protein Folding; D017434:Protein Structure, Tertiary; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D000509:alpha-Fetoproteins / Q000378:metabolism*
D002352:Carrier Proteins; D037102:Lectins; D037241:Mannose-Binding Lectins; D037121:Plant Lectins; D000509:alpha-Fetoproteins; D008358:Mannose