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ABSTRACT: The crystal structure of a thermostable endo-1,5-alpha-L-arabinanase, ABN-TS, from Bacillus thermodenitrificans TS-3 was determined at 1.9 A to an R-factor of 18.3% and an R-free-factor of 22.5%. The enzyme molecule has a five-bladed beta-propeller fold. The substrate-binding cleft formed across one face of the propeller is open on both sides to allow random binding of several sugar units in the polymeric substrate arabinan. The beta-propeller fold is stabilized through a ring closure. ABN-TS exhibits a new closure-mode involving residues in the N-terminal region: Phe7 to Gly21 exhibit hydrogen bonds and hydrophobic interactions with the first and last blades, and Phe4 links the second and third blades through a hydrogen bond and an aromatic stacking interaction, respectively. The role of the N-terminal region in the thermostability was confirmed with a mutant lacking 16 amino acid residues from the N-terminus of ABN-TS.
Journal of Biochemistry 06/2005; 137(5):587-92. · 2.37 Impact Factor
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ABSTRACT: A thermostable endo-1,5-alpha-L-arabinanase ABN-TS from Bacillus thermodenitrificans TS-3 with a molecular weight of 35 kDa was crystallized by the hanging-drop vapour-diffusion method using sodium citrate as a precipitant. The crystals were loop-mounted in a cryoprotectant solution containing 28%(w/v) sucrose and 1 M sodium citrate pH 6.0 and flash-cooled. Sucrose was selected as the most suitable cryoprotectant. The crystal belonged to the orthorhombic space group P2(1)2(1)2(1), with unit-cell parameters a = 40.3, b = 77.8, c = 89.7 angstroms. The calculated VM based on one molecule per asymmetric unit was 2.0 angstroms3 Da(-1). A complete data set from a frozen crystal was collected to 1.9 angstroms resolution using synchrotron radiation at SPring-8. A molecular-replacement solution was obtained using the structure of alpha-arabinanase 43A from Cellvibrio japonicus.
Acta Crystallographica Section D Biological Crystallography 07/2004; 60(Pt 6):1149-51. · 12.62 Impact Factor
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ABSTRACT: Corn fiber (CNF) is an abundant by-product of the wet corn milling process used to produce corn starch. In light of the need to recycle organic wastes, the effects of adding a hot water-soluble fraction (HWSF) from CNF to a medium on the vegetative mycelial growth of nine edible mushrooms such as Lentinula edodes and Pholiota nameko were investigated. The results showed that the mycelial growth of these fungi was markedly increased (1.4–9.5 times that of the control) by adding 5%–20% CNF-HWSF to the medium. These promotive effects were also apparent on mycorrhizal mushrooms, such as Tricholoma matsutake (3.3-fold) and Lyophyllium shimeji (3.7-fold). The promotive effects on mycelial growth were shown in the low-molecular-weight fractions (molecular weight <500 daltons) prepared from CNF-HWSF. The promotive actions were more effective on slow-growing mushrooms (L. edodes and P. nameko) than on rapidly growing mushrooms (Pleurotus ostreatus and Flammulina velutipes). The results obtained in this experiment suggest that CNF-HWSF can be used as a promotive substance for cultivating edible mushrooms.
Journal of Wood Science 09/2003; 49(5):437-443. · 0.96 Impact Factor
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ABSTRACT: The thermostable pectate lyase PL 47 from Bacillus sp. TS 47, with a molecular weight of 50 kDa, was crystallized by the hanging-drop vapour-diffusion method using 2-propanol and polyethylene glycol 4000 as precipitants. The crystals belong to the trigonal space group P3(1)21, with unit-cell parameters a = b = 58.8, c = 229.7 A, gamma = 120 degrees. The calculated V(M) based on one molecule per asymmetric unit is 2.30 A(3) Da(-1). A native data set from a frozen crystal was collected to 1.8 A resolution using synchrotron radiation at SPring-8. A molecular-replacement solution was obtained using the structure of pectate lyase from B. subtilis as a model.
Acta Crystallographica Section D Biological Crystallography 03/2003; 59(Pt 2):341-2. · 12.62 Impact Factor
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ABSTRACT: A strain of a thermophilic bacterium, tentatively designated Bacillus thermodenitrificans TS-3, with arabinan-degrading activity was isolated. It produced an endo-arabinase (ABN) (EC 3.2.1.99) and two arabinofuranosidases (EC 3.2.1.55) extracellularly when grown at 60 degrees C on a medium containing sugar beet arabinan. The ABN (tentatively called an ABN-TS) was purified 7,417-fold by anion-exchange, hydrophobic, size exclusion, and hydroxyapatite chromatographies. The molecular mass of ABN-TS was 35 kDa as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and the isoelectric point was pH 4.5. The enzyme was observed to be more thermostable than known ABNs; it had a half-life of 4 h at 75 degrees C. The enzyme had optimal activity at 70 degrees C and pH 6.0. The enzyme had apparent K(m) values of 8.5 and 45 mg/ml and apparent V(max) values of 1.6 and 1.1 mmol/min/mg of protein against debranched arabinan (alpha-1,5-arabinan) and arabinan, respectively. The enzyme had no pectin-releasing activity (protopectinase activity) from sugar beet protopectin, differing from an ABN (protopectinase-C) from mesophilic Bacillus subtilis IFO 3134. The pattern of degradation of debranched arabinan by ABN-TS indicated that the enzyme was an endo-acting enzyme and the main end products were arabinobiose and arabinose. The results of preliminary experiments indicated that the culture filtrate of strain TS-3 is suitable for L-arabinose production from sugar beet pulp at high temperature.
Applied and Environmental Microbiology 05/2002; 68(4):1639-46. · 3.83 Impact Factor
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ABSTRACT: The gene that encodes a thermostable endo-arabinase (called ABN-TS) from Bacillus thermodenitrificans TS-3 was cloned, sequenced, and expressed in the mesophilic B. subtilis. The gene contained an open reading frame consists of 939 bp, which encodes 313 amino acids. The deduced amino acid sequence of the enzyme showed 50, 46, and 36% similarity with endo-arabinase from B. subtilis IFO 3134 (PPase-C), Pseudomonas fluorescens (ArbA), and Aspergillus niger (ABNA), respectively. The hydrophobic and acidic amino acids making up ABN-TS outnumbered those in PPase-C. The gene product expressed in B. subtilis, as the host, had substantially the same characteristics, and was stable up to 70 degrees C, and the reaction was optimal around 70 degrees C, as well as native ABN-TS.
Bioscience Biotechnology and Biochemistry 03/2002; 66(2):430-3. · 1.28 Impact Factor
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ABSTRACT: Trehalase from the culture filtrate ofLentinula edodes was purified and characterized. Molecular masses were estimated to be 158 kDa and 79–91 kDa by gel filtration and SDS-PAGE
under the reduced condition, respectively. The enzyme was composed of two identical subunits and contained carbohydrate molecules.
The optimum temperature and pH were obtained at around 40°C and pH 5.0, respectively. The enzyme was stable up to 40°C and
in a range pH of 4–10 at 30°C. It cleaved α-1,1 linkages of trehalose, but not α-1,4, α-1,6 or β-1,4 glycosyl linkages, and
was defined as an acid trehalase.
Mycoscience 09/2001; 42(5):479-482. · 1.21 Impact Factor
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ABSTRACT: When Moraxella plasmid pUO1 encoding haloacetate dehalogenase and mercury resistance coexisted with IncP-1 plasmid RP4 in Pseudomonas sp., genetic exchange between the plasmids often occurred, probably by site-specific recombination. The recombinant plasmids obtained were classified into four groups on the basis of phenotype. Representative plasmids for each group were analyzed for DNA composition and function, and the mechanism for the formation of these plasmids was sought. They were inherited stably in Escherichia coli and a Pseudomonas sp.
Applied and Environmental Microbiology 07/1985; 49(6):1544-6. · 3.83 Impact Factor
