2.4.1.248	evolution	CITase belongs to glycoside hydrolase family 66, GH6	
2.4.1.248	evolution	CITase is a member of the glycoside hydrolase family 66, GH66	
2.4.1.248	malfunction	15 deletion mutant enzymes. M123DELTA (R4-deleted), MDELTA234 (R1-deleted), and MDELTA23DELTA (R1/R4-deleted) catalyze cycloisomaltooligosaccharide synthesis, but other mutants are inactive. M123DELTA, MDELTA234, and MDELTA23DELTA increase their Km values against dextran 40. The wild-type enzyme and M123DELTA produced cycloisomaltooligosaccharide-8 predominantly, but MDELTA234 and MDELTA23DELTA lose cycloisomaltooligosaccharide-8 production specificity. The kcat values of MDELTA234 and MDELTA23DELTA decrease, and these mutants show narrowed temperature and pH stability ranges	
2.4.1.248	additional information	catalytically important residues of CITase-598K are Asp144, Asp269, and Glu341	
2.4.1.248	physiological function	CITase production is induced by dextran 40, isomaltose, isomaltotriose, and panose, and soluble starch but not by G67 or dextrin, which suggests that alpha-1,6 glucosidic linkages are required for CITase induction. Although CITase is induced by isomaltose, isomaltotriose, and panose, no cyclodextrans are produced in the culture. Cyclodextran-producing activity in the presence of soluble starch as the substrate is observed only in cultures containing dextran 40 or soluble starch. The production of CITase is significantly unaffected by glucose addition, but soluble starch-CITase activity almost completely disappears after glucose addition. A 135-kDa protein contributes to cyclodextran formation from starch in the presence of CITase