Recognition of cellooligosaccharides by a family 28 carbohydrate-binding module.
The crystal structures of a carbohydrate-binding module (CBM) family 28 domain of endoglucanase Cel5A from Clostridium josui have been determined in ligand-free and complex forms with cellobiose, cellotetraose, and cellopentaose as the first complex structures of this family. In the cleft of a beta-sandwich fold, the ligands are recognized by stacking interactions and hydrogen bonds. Conformations of the bound cellooligosaccharides are similar to those in crystals and solution but clearly different from the cellulose structure. Interestingly, the glucan chain bound on CBM28 is in the opposite direction of that bound to CBM17, although these families share significant structural similarity.
Department of Biotechnology, The University of Tokyo, Tokyo, Japan.
Kazuhide
K
Tsukimoto
Rie
R
Takada
Yuko
Y
Araki
Kentaro
K
Suzuki
Shuichi
S
Karita
Takayoshi
T
Wakagi
Hirofumi
H
Shoun
Takashi
T
Watanabe
Shinya
S
Fushinobu
D001665:Binding Sites; D002475:Cellobiose / Q000378:metabolism; D002480:Cellulase / Q000737:chemistry* / Q000378:metabolism*; D003013:Clostridium / Q000201:enzymology / Q000378:metabolism; D008024:Ligands; D008958:Models, Molecular; D005810:Multigene Family; D009844:Oligosaccharides / Q000302:isolation & purification / Q000378:metabolism*; D011485:Protein Binding / Q000502:physiology; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D011956:Receptors, Cell Surface / Q000737:chemistry* / Q000378:metabolism*; D040681:Structural Homology, Protein
D008024:Ligands; D009844:Oligosaccharides; D011956:Receptors, Cell Surface; C055213:saccharide-binding proteins; D002475:Cellobiose; C407024:endoglucanase Cel5A; D002480:Cellulase