TY - JOUR
T1 - β-d-xylosidase from geobacillus thermoleovorans IT-08
T2 - Biochemical characterization and bioinformatics of the enzyme
AU - Ratnadewi, Anak Agung Istri
AU - Fanani, Muchzainal
AU - Kurniasih, Sari Dewi
AU - Sakka, Makiko
AU - Wasito, Eddy Bagus
AU - Sakka, Kazuo
AU - Nurachman, Zeily
AU - Puspaningsih, Ni Nyoman Tri
N1 - Funding Information:
Acknowledgments This research was partially supported from the Directorate General of Higher Education, Ministry of Education and Culture, the Republic of Indonesia through Hibah Tim Pascasarjana Program to NNTP (2011–2012), Sandwich Course Program 2011 to AAID, as well as Hibah Doktor Program to AAID. We thank Mr. Kimiya Mizutani for his assistance in the preparation of enzyme purification, Mr. Didik Huswo Utomo for molecular art work as well as Mr. Tubagus Andhika Nugraha for critical reading of this manuscript.
PY - 2013/8
Y1 - 2013/8
N2 - The gene encoding a thermostable β-d-xylosidase (GbtXyl43B) from Geobacillus thermoleovorans IT-08 was cloned in pET30a and expressed in Escherichia coli; additionally, characterization and kinetic analysis of GbtXyl43B were carried out. The gene product was purified to apparent homogeneity showing M r of 72 by sodium dodecyl sulfate polyacrylamide gel electrophoresis. The enzyme exhibited an optimum temperature and pH of 60 C and 6.0, respectively. In terms of stability, GbtXyl43B was stable at 60 C at pH 6.0 for 1 h as well as at pH 6-8 at 4 C for 24 h. The enzyme had a catalytic efficiency (k cat/K M) of 0.0048 ± 0.0010 s-1 mM-1 on p-nitrophenyl-β-d- xylopyranoside substrate. Thin layer chromatography product analysis indicated that GbtXyl43B was exoglycosidase cleaving single xylose units from the nonreducing end of xylan. The activity of GbtXyl43B on insoluble xylan was eightfold higher than on soluble xylan. Bioinformatics analysis showed that GbtXyl43B belonging to glycoside hydrolase family 43 contained carbohydrate-binding module (CBM; residues 15 to 149 forming eight antiparallel β-strands) and catalytic module (residues 157 to 604 forming five-bladed β-propeller fold with predicted catalytic residues to be Asp287 and Glu476). CBM of GbtXyl43B dominated by the Phe residues which grip the carbohydrate is proposed as a novel CBM36 subfamily.
AB - The gene encoding a thermostable β-d-xylosidase (GbtXyl43B) from Geobacillus thermoleovorans IT-08 was cloned in pET30a and expressed in Escherichia coli; additionally, characterization and kinetic analysis of GbtXyl43B were carried out. The gene product was purified to apparent homogeneity showing M r of 72 by sodium dodecyl sulfate polyacrylamide gel electrophoresis. The enzyme exhibited an optimum temperature and pH of 60 C and 6.0, respectively. In terms of stability, GbtXyl43B was stable at 60 C at pH 6.0 for 1 h as well as at pH 6-8 at 4 C for 24 h. The enzyme had a catalytic efficiency (k cat/K M) of 0.0048 ± 0.0010 s-1 mM-1 on p-nitrophenyl-β-d- xylopyranoside substrate. Thin layer chromatography product analysis indicated that GbtXyl43B was exoglycosidase cleaving single xylose units from the nonreducing end of xylan. The activity of GbtXyl43B on insoluble xylan was eightfold higher than on soluble xylan. Bioinformatics analysis showed that GbtXyl43B belonging to glycoside hydrolase family 43 contained carbohydrate-binding module (CBM; residues 15 to 149 forming eight antiparallel β-strands) and catalytic module (residues 157 to 604 forming five-bladed β-propeller fold with predicted catalytic residues to be Asp287 and Glu476). CBM of GbtXyl43B dominated by the Phe residues which grip the carbohydrate is proposed as a novel CBM36 subfamily.
KW - CBM36
KW - GH 43
KW - Geobacillus thermoleovorans
KW - IT-08
KW - Xylanase
KW - β-d-xylosidase
UR - http://www.scopus.com/inward/record.url?scp=84881279830&partnerID=8YFLogxK
U2 - 10.1007/s12010-013-0329-5
DO - 10.1007/s12010-013-0329-5
M3 - Article
C2 - 23797510
AN - SCOPUS:84881279830
SN - 0273-2289
VL - 170
SP - 1950
EP - 1964
JO - Applied Biochemistry and Biotechnology
JF - Applied Biochemistry and Biotechnology
IS - 8
ER -