Cloning of the cyclodextrin glucanotransferase gene from alkalophilic Bacillus sp. A2-5a and analysis of the raw starch-binding domain

2000 ◽  
Vol 53 (4) ◽  
pp. 430-434 ◽  
Author(s):  
K. Ohdan ◽  
T. Kuriki ◽  
H. Takata ◽  
S. Okada
Keyword(s):  
Binding Domain ◽  
Cyclodextrin Glucanotransferase ◽  
Bacillus Sp ◽  
Raw Starch ◽  
Raw Starch Binding ◽  
Alkalophilic Bacillus

scholarly journals New type of starch-binding domain: the direct repeat motif in the C-terminal region of Bacillus sp. no. 195 α-amylase contributes to starch binding and raw starch degrading

2000 ◽  
Vol 350 (2) ◽  
pp. 477-484 ◽  
Author(s):  
Jun-ichi SUMITANI ◽  
Tadashi TOTTORI ◽  
Takashi KAWAGUCHI ◽  
Motoo ARAI
Keyword(s):  
Molecular Mass ◽  
Catalytic Domain ◽  
Direct Repeat ◽  
Repeat Sequence ◽  
Binding Domain ◽  
Terminal Region ◽  
Proteolytic Processing ◽  
Bacillus Sp ◽  
Raw Starch ◽  
Raw Starch Binding

The α-amylase from Bacillus sp. no. 195 (BAA) consists of two domains: one is the catalytic domain similar to α-amylases from animals and Streptomyces in the N-terminal region; the other is the functionally unknown domain composed of an approx. 90-residue direct repeat in the C-terminal region. The gene coding for BAA was expressed in Streptomyces lividans TK24. Three active forms of the gene products were found. The pHand thermal profiles of BAAs, and their catalytic activities for p-nitrophenyl maltopentaoside and soluble starch, showed almost the same behaviours. The largest, 69kDa, form (BAA-α) was of the same molecular mass as that of the mature protein estimated from the nucleotide sequence, and had raw-starch-binding and -degrading abilities. The second largest, 60kDa, form (BAA-β), whose molecular mass was the same as that of the natural enzyme from Bacillus sp. no. 195, was generated by proteolytic processing between the two repeat sequences in the C-terminal region, and had lower activities for raw starch binding and degrading than those of BAA-α. The smallest, 50kDa, form (BAA-γ) contained only the N-terminal catalytic domain as a result of removal of the C-terminal repeat sequence, which led to loss of binding and degradation of insoluble starches. Thus the starch adsorption capacity and raw-starch-degrading activity of BAAs depends on the existence of the repeat sequence in the C-terminal region. BAA-α was specifically adsorbed on starch or dextran (α-1,4 or α-1,6glucan), and specifically desorbed with maltose or β-cyclodextrin. These observations indicated that the repeat sequence of the enzyme was functional in the starch-binding domain (SBD). We propose the designation of the homologues to the SBD of glucoamylase from Aspergillus niger as family I SBDs, the homologues to that of glucoamylase from Rhizopus oryzae as family II, and the homologues of this repeat sequence of BAA as family III.

Production of cyclodextrin glucanotransferase (CGTase) from alkalophilic Bacillus sp. TS1-1: media optimization using experimental design

2004 ◽  
Vol 35 (5) ◽  
pp. 467-473 ◽  
Author(s):  
Mohd Khairizal Mahat ◽  
Rosli Md. Illias ◽  
Roshanida A. Rahman ◽  
Noor Aini Abd Rashid ◽  
Nik Azmi Nik Mahmood ◽  
...  
Keyword(s):  
Experimental Design ◽  
Cyclodextrin Glucanotransferase ◽  
Media Optimization ◽  
Bacillus Sp ◽  
Alkalophilic Bacillus
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