Identification of a new quaternary association for legume lectins.
Lotus tetragonolobus lectin (LTA) is a fucose-specific legume lectin. Although several studies report a diverse combination of biological activities for LTA, little is known about the mechanisms involved in l-fucosyl oligosaccharide recognition. The crystal structure of LTA at 2.0A resolution reveals a different legume lectin tetramer. Its structure consists of a homotetramer composed of two back-to-back GS4-like dimers arranged in a new mode, resulting in a novel tetramer. The LTA N-linked carbohydrate at Asn4 and the unusual LTA dimer-dimer interaction are related to its particular mode of tetramerization. In addition, we used small angle X-ray scattering to investigate the quaternary structure of LTA in solution and to compare it to the crystalline structure. Although the crystal structure of LTA has revealed a conserved metal-binding site, its l-fucose-binding site presents some punctual differences. Our investigation of the new tetramer of LTA and its fucose-binding site is essential for further studies related to cross-linking between LTA and complex divalent l-fucosyl carbohydrates.
Moreno
Frederico Bruno Mendes Batista
FB
Curso de Pós-graduação em Biofísica Molecular, Departamento de Física, Universidade Estadual Paulista Júlio de Mesquita Filho, R. Cristovão Colombo, 2265, Nazareth, São José do Rio Preto, São Paulo, Brazil.
de Oliveira
Taianá Maia
TM
Martil
Daiana Evelin
DE
Viçoti
Magno Massolino
MM
Bezerra
Gustavo Arruda
GA
Abrego
José Ramon Beltran
JR
Cavada
Benildo Sousa
BS
Filgueira de Azevedo
Walter
W
D000595:Amino Acid Sequence; D001665:Binding Sites; D018360:Crystallography, X-Ray; D019281:Dimerization; D005643:Fucose / Q000737:chemistry; D037102:Lectins / Q000737:chemistry*; D000070116:Lotus; D008969:Molecular Sequence Data; D037121:Plant Lectins / Q000737:chemistry*; D020836:Protein Structure, Quaternary; D012542:Scattering, Radiation
D037102:Lectins; D037121:Plant Lectins; C027112:fucose-binding lectin; D005643:Fucose