C-terminal domain of β-1,3-glucanase H in Bacillus circulans IAM1165 has a role in binding to insoluble β-1,3-glucan

The deduced amino acid sequences of 72-kDa beta-1,3-glucanase from Bacillus cir circulans WL-12 (GlcA) and 91-kDa enzyme from B. circulans IAM1165 (BglH) are highly homologous, except that the latter has an additional long C-terminal region composed of 192 amino acid residues. Two mutant enzymes (BglH deprived of the C-terminal region and GlcA with the C-terminal region added),were constructed. The enzymes possessing the C-terminal region bound more abundantly to pachyman (insoluble beta-1,3-glucan) and Aspergillus oryzae cell mall than those not possessing the region. This indicates that the C-terminal region participated in binding of the enzymes to insoluble beta-1,3-glucan, (C) 1998 Federation of European Biochemical Societies.