Characterization of a type D1A EUL-related lectin from rice expressed in Pichia pastoris.
OrysaEULD1A is one of the five EUL genes in rice (Oryza sativa) encoding a putative carbohydrate-binding protein belonging to the family of Euonymus related lectins (EUL). The OrysaEULD1A sequence comprises two highly similar EUL domains (91% sequence similarity and 72% sequence identity) separated by a 23 amino acid linker sequence and preceded by a 19 amino acid N-terminal sequence. In the present study, the full-length protein OrysaEULD1A as well as its individual domains OrysaEULD1A domain 1 and 2 were expressed in Pichia pastoris. After purification of the recombinant proteins, their carbohydrate-binding specificity was analyzed and compared. Interestingly, all recombinant lectins showed clear specificity towards galactosylated structures. Furthermore, all recombinant proteins agglutinated red blood cells, indicating that the full-length protein OrysaEULD1A and its domains are true lectins. These results taken together with data previously reported for single-domain EUL proteins indicate that although the amino acids--responsible for the formation of the carbohydrate-binding site--are identical for all EUL proteins in rice, these lectins show different carbohydrate specificities. This promiscuity of the carbohydrate-binding site can be attributed to gene divergence.
Bassam
B
Al Atalah
Dieter
D
Vanderschaeghe
Yehudi
Y
Bloch
Paul
P
Proost
Kirsten
K
Plas
Nico
N
Callewaert
Savvas N
SN
Savvides
Els J M
EJ
Van Damme
D000595:Amino Acid Sequence; D008969:Molecular Sequence Data; D012275:Oryza / Q000235:genetics*; D010843:Pichia / Q000235:genetics / Q000378:metabolism*; D037121:Plant Lectins / Q000737:chemistry* / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000235:genetics; D016415:Sequence Alignment
D037121:Plant Lectins; D011994:Recombinant Proteins