Crystal structure of a conger eel galectin (congerin II) at 1.45A resolution: implication for the accelerated evolution of a new ligand-binding site following gene duplication.
The crystal structure of congerin II, a galectin family lectin from conger eel, was determined at 1.45A resolution. The previously determined structure of its isoform, congerin I, had revealed a fold evolution via strand swap; however, the structure of congerin II described here resembles other prototype galectins. A comparison of the two congerin genes with that of several other galectins suggests acceralated evolution of both congerin genes following gene duplication. The presence of a Mes (2-[N-morpholino]ethanesulfonic acid) molecule near the carbohydrate-binding site in the crystal structure points to the possibility of an additional binding site in congerin II. The binding site consists of a group of residues that had been replaced following gene duplication suggesting that the binding site was built under selective pressure. Congerin II may be a protein specialized for biological defense with an affinity for target carbohydrates on parasites' cell surface.
Department of Biotechnology and Biomaterial Chemistry, Graduate School of Engineering, Nagoya University, Chikusa-Ku, Japan. i45282a@nucc.cc.nagoya-u.ac.jp
Tsuyoshi
T
Shirai
Yuuka
Y
Matsui
Clara
C
Shionyu-Mitsuyama
Takashi
T
Yamane
Hisao
H
Kamiya
Chihiro
C
Ishii
Tomohisa
T
Ogawa
Koji
K
Muramoto
D017738:Alkanesulfonic Acids / Q000378:metabolism; D000818:Animals; D001665:Binding Sites; D050260:Carbohydrate Metabolism; D018360:Crystallography, X-Ray; D019143:Evolution, Molecular; D037161:Galectins; D020440:Gene Duplication; D006801:Humans; D037102:Lectins / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D008024:Ligands; D008957:Models, Genetic; D008958:Models, Molecular; D009025:Morpholines / Q000378:metabolism; D010802:Phylogeny; D012680:Sensitivity and Specificity
D017738:Alkanesulfonic Acids; D037161:Galectins; D037102:Lectins; D008024:Ligands; D009025:Morpholines; C122080:congerin II protein, Conger eel; C004550:2-(N-morpholino)ethanesulfonic acid