Interaction between the CBM of Cel9A from Thermobifida fusca and cellulose fibers.
Molecular docking and molecular dynamics (MD) simulations were used to investigate the binding of a cellodextrin chain in a crystal-like conformation to the carbohydrate-binding module (CBM) of Cel9A from Thermobifida fusca. The fiber was found to bind to the CBM in a single and well-defined configuration in-line with the catalytic cleft, supporting the hypothesis that this CBM plays a role in the catalysis by feeding the catalytic domain (CD) with a polysaccharide chain. The results also expand the current known list of residues involved in the binding. The polysaccharide-protein attachment is shown to be mediated by five amine/amide-containing residues. E478 and E559 were found not to interact directly with the sugar chain; instead they seem to be responsible to stabilize the binding motif via hydrogen bonds.
Pacific Northwest National Laboratory, Richland, WA 99352, USA.
Osmair V
OV
Oliveira
Luiz C G
LC
Freitas
T P
TP
Straatsma
Roberto D
RD
Lins
D000192:Actinomycetales / Q000201:enzymology*; D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism*; D001665:Binding Sites; D020134:Catalytic Domain; D002482:Cellulose / Q000737:chemistry* / Q000378:metabolism*; D003198:Computer Simulation; D006860:Hydrogen Bonding; D008958:Models, Molecular; D011485:Protein Binding
D001426:Bacterial Proteins; D002482:Cellulose