Crystal structure of the catalytic domain of the beta-1,4-glycanase Cex from Cellulomonas fimi

Determination of the high-resolution crystal structure of the Cex catalytic domain in Cellulomonas fimi reveals that the crystal structure contains 2400 protein atoms, 0.217 R-factor and 45 water molecules at a resolution of 1.8 Angstrom units. The folding of the protein into an eight-parallel-stranded alpha/beta-barrel is new for the microbial beta-glycanase Cex. While the active site exists as an open cleft on the alpha/beta-barrel carboxy-terminal, the hydrogen bonding network in the domain stabilizes the ionization states of vital residues for regulating the equilibrium of the reactions.