title: Molecular cloning, purification and characterization of thermostable beta-1,3-1,4 glucanase from Bacillus subtilis A8-8.
abstract: A gene encoding a beta-1,3-1,4-glucanase (CelA) belonging to family 5 of glycoside hydrolases was cloned and sequenced from the Bacillus subtilis A8-8. The open-reading-frame of celA comprised 1499 base pairs and the enzyme was composed of 500 amino acids with a molecular mass of 55 kDa. The recombinant beta-1,3-1,4 glucanase was purified by GST-fusion purification system. The pH and temperature optima of the enzyme were 8.0 and 60 degrees C, respectively. The enzyme was stable within pH 6.0-9.0. It was stable up to 60 degrees C and retained 30% of its original activity at 70 degrees C for 60 min. It hydrolyzed lichenan, CMC, xylan, laminarin, avicel and pNPC, but was inactive towards cellobiose. The enzyme activity was markedly activated by Co2+ and Mn2+, but was strongly inactivated by Fe3+. The truncated gene, devoid of cellulose-binding domain (CBD) showed 60% of activity and bound to avicel.
authors.affiliation: Dept. of Biotechnology, College of Natural Resources and Life Science, Dong-A University, Busan 604-714, Republic of Korea.
authors.forename: Youn-Ju
authors.initials: YJ
authors.lastname: Jung
authors.forename: Yong-Seok
authors.initials: YS
authors.lastname: Lee
authors.forename: In-Hye
authors.initials: IH
authors.lastname: Park
authors.forename: M Subhosh
authors.initials: MS
authors.lastname: Chandra
authors.forename: Keun-Ki
authors.initials: KK
authors.lastname: Kim
authors.forename: Yong-Lark
authors.initials: YL
authors.lastname: Choi
mesh_terms: D001412:Bacillus subtilis / Q000201:enzymology* / Q000235:genetics*; D020134:Catalytic Domain; D002482:Cellulose / Q000737:chemistry; D003001:Cloning, Molecular; D003035:Cobalt / Q000737:chemistry; D044644:Endo-1,3(4)-beta-Glucanase / Q000737:chemistry*; D005936:Glucans / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D008345:Manganese / Q000737:chemistry; D011134:Polysaccharides / Q000737:chemistry; D011994:Recombinant Proteins / Q000737:chemistry; D013696:Temperature; D014990:Xylans / Q000737:chemistry
chemical_list: D005936:Glucans; D011134:Polysaccharides; D011994:Recombinant Proteins; D014990:Xylans; D003035:Cobalt; D008345:Manganese; D002482:Cellulose; C008247:laminaran; D044644:Endo-1,3(4)-beta-Glucanase; C015968:lichenin