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K Tonomura

Publications and source records attributed to K Tonomura.

At least 19 recordsLinked to original sources
PubMed1999

Sequence analysis of 18S-28S rRNA spacer regions from Saccharomyces kunashirensis, S. martiniae, S. rosinii, and S. transvaalensis.

Sequences of two internal transcribed spacer regions between 18S and 28S rRNA for recently described yeasts species, Saccharomyces kunashirensis, S. martiniae, S. rosinii, and S. transvaalensis, were determined to assess their phylogenetic relationship to the other Saccharomyces species. In the two phylogenetic trees constructed by the neighbor-joining method, independent branches reflected that delimitation of the four new species was valid.

Molecular Sequence Data↗
PubMed1998

Expression of the extracellular levansucrase and invertase genes from Zymomonas mobilis in Escherichia coli cells.

We investigated the expression and localization in Escherichia coli of sucZE2 and sucZE3, encoding Zymomonas mobilis extracellular levansucrase and invertase, respectively, and lacking a typical N-terminal secretion signal. Levansucrase and invertase were expressed efficiently under the lac and tac promoters in E. coli cells, and some of the levansucrase produced was localized in the periplasmic space. The sucZE2 expression was not lethal to E. coli in the presence of 5% sucrose, and led to the accumulation of levan from sucrose.

Amino Acid Sequence↗
PubMed1997

Polycaprolactone depolymerase produced by the bacterium Alcaligenes faecalis.

Several microorganisms were isolated as bacteria degrading polycaprolactone (PCL), and one of them, a strain B273 identified as Alcaligenes faecalis, was selected. Because this strain produced only slight PCL depolymerase activity, the hyperproducing mutant, TS22, was isolated after UV irradiation. Synthesis of PCL depolymerase was derepressed, probably based on the altered regulation of metabolic pathways in strain TS22. The partially purified enzyme hydrolyzed p-nitrophenyl fatty acids and triglycerides other than PCL, but not poly(3-hydroxybutyrate), indicating that PCL depolymerase may be a kind of lipase.

Alcaligenes↗
PubMed1997

A phylogenetic analysis of Saccharomyces species by the sequence of 18S-28S rRNA spacer regions.

Sequences of two internally transcribed spacer regions between 18S and 28S rRNA genes were determined to assess the phylogenetic relationship in the strains belonging to the genus Saccharomyces. The sequences of S. bayanus and S. pastorianus were quite similar, but not identical. Two phylogenetic trees constructed by the neighbor-joining method showed that all the species examined were distinguished from one another. The Saccharomyces sensu stricto species: S. cerevisiae, S. bayanus, S. paradoxus and S. pastorianus, were closely related and far from the Saccharomyces sensu lato species including S. barnetti, S. castellii, S. dairensis, S. exiguus, S. servazzii, S. spencerorum and S. unisporus, and an outlying species, S. kluyveri.

DNA, Fungal↗
PubMed1997

Purification and properties of poly(3-hydroxybutyrate) depolymerase from the fungus Paecilomyces lilacinus D218.

Poly(3-hydroxybutyrate) depolymerase was purified to homogeneity from the culture filtrate of Paecilomyces lilacinus D218 by column chromatography on CM-Toyopearl 650M and hydroxylapatite. The molecular weight of the enzyme was estimated to be 48,000 by SDS-PAGE. Maximal activity was observed near pH 7.0 and 45 degrees C. The Km and Vmax values for PHB were 0.13(mg/ml) and 3750 (U/mg protein), respectively. The enzyme hydrolyzed PHB and p-nitrophenyl fatty acids but not polycaprolactone and triglycerides.

Carboxylic Ester Hydrolases↗
PubMed1997

Reexamination of yeast strains classified as Torulaspora delbrueckii (Lindner).

Twenty-eight yeast strains presumed to represent Torulaspora delbrueckii were analyzed by randomly amplified polymorphic DNA-PCR analysis. Four strains (HUT 7161, IFO 1138, IFO 1145, and IFO 1956) that were considerably different from the type strain were further investigated. Morphological and physiological characteristics revealed that strains HUT 7161 and IFO 1145 belong to the genus Debaryomyces rather than the genus Torulaspora, and the former strain may represent Debaryomyces hansenii. Strains IFO 1138 and IFO 1956 were classified as either Saccharomyces castellii or Saccharomyces dairensis by identification keys involving physiological tests. On the basis of analysis of the sequences of two rRNA internal spacer regions, strains IFO 1138 and IFO 1956 were closely related to S. castellii and strains HUT 7161 and IFO 1145 were outside members of the genera Torulaspora, Zygosaccharomyces, and Saccharomyces.

Ascomycota↗
PubMed1996

Detection of maltose fermentation genes in the baking yeast strains of Saccharomyces cerevisiae.

The presence of any one of the five unlinked MAL loci (MAL1, MAL2, MAL3, MAL4 and MAL6) confers the ability to ferment maltose on the yeast Saccharomyces cerevisiae. Each locus is composed of three genes encoding maltose permease, alpha-glucosidase and MAL activator. Chromosomal DNA of seven representative baking strains has been separated by pulse-field gel electrophoresis and probed with three genes in MAL6 locus. The DNA bands to which all of the three MAL-derived probes simultaneously hybridized were chromosome VII carrying MAL1 in all of the strains tested, chromosome XI carrying MAL4 in six strains, chromosome III carrying MAL2 in three strains and chromosomes II and VIII carrying MAL3 and MAL6, respectively, in the one strain. The number of MAL loci in baking strains was comparable to those of brewing strains.

Chromosomes, Fungal↗
PubMed1995

Molecular genetic properties of the yeast Torulaspora pretoriensis: characterization of chromosomal DNA and genetic transformation by Saccharomyces cerevisiae-based plasmids.

Chromosomal DNA banding patterns were obtained for three strains of Torulaspora pretoriensis by contour-clamped homogeneous-electric-field gel electrophoresis. Chromosomes were resolved into six or seven bands in the range of 800 to 2000 kb, and a polymorphism of these lengths was observed. By Southern-blot analysis, the three strains were shown to lack the DNA sequences homologous to the URA3, LEU2, TRP1, and HO genes of Saccharomyces cerevisiae. A uracil auxotrophic mutant derived from T. pretoriensis was transformed with three plasmids (YEp24, YRpHI, and YCp50) carrying the URA3 gene of S. cerevisiae by the lithium acetate method.

Blotting, Southern↗
PubMed1995

Use of haloacetate dehalogenase genes as selection markers for Escherichia coli and Pseudomonas vectors.

The haloacetate dehalogenase gene, dehH2, cloned from Moraxella sp. strain B could be used a selection marker gene for vectors in Escherichia coli and Pseudomonas putida. Haloacetates, especially iodoacetate, inhibit the growth of some microorganisms. The dehH2 gene introduced into the cells conferred iodoacetate resistance on them. Therefore, E. coli and P. putida transformed with vectors marked with dehH2 could be easily selected on plates containing iodoacetate.

Acetates↗
PubMed1995

Electrophoretic karyotyping of the yeast genus Torulaspora.

Karyotypes of yeast strains in the genus Torulaspora were determined by pulse-field gel electrophoresis and compared with those of the related genus Zygosaccharomyces. The DNA bands ranged from 800 to 1600 kb in T. delbrueckii and 800 to 2000 kb in both T. globosa and T. pretoriensis and those numbers were about six in the three species. The chromosomes of Torulaspora strains comprised relatively smaller size of DNAs than Zygosaccharomyces strains.

DNA, Fungal↗
PubMed1995

Cloning and characterization of Zymomonas mobilis genes encoding extracellular levansucrase and invertase.

The genes encoding the extracellular levansucrase and invertase of Zymomonas mobilis have been cloned and sequenced. The levansucrase gene, sucZE2, spans 1269 bp and encodes an M(r) 46,790 polypeptide, and the invertase gene, sucZE3, is of 1239 bp and encodes an M(r) 46,110 polypeptide. The 5'-terminal sequences of both genes corresponded to the N-terminal amino acid sequences of the secreted levansucrase and invertase, implying that the secretion of both enzymes does not involve proteolytic processing of the N-terminals. Both enzyme molecules appear to carry no typical N-terminal secretion signal. Significant homology between sucZE2 and sucZE3 was observed, but both genes showed no homology to the gene encoding an intracellular invertase coexisting in Z. mobilis. Two genes, sucZE2 and sucZE3, are possibly placed in an operon because the expression of two genes were simultaneously controlled by the regulator gene zliE, previously identified.

Amino Acid Sequence↗
PubMed1994

Cloning and sequence analysis of a plasmid-encoded 2-haloacid dehalogenase gene from Pseudomonas putida No. 109.

The 2-haloacid dehalogenase of Pseudomonas putida No. 109 was mediated by a 74-kb conjugative plasmid, which was transferred by mating into Pseudomonas and Escherichia coli and there expressed the dehalogenase. A 2.8-kb EcoRI-fragment generated from the plasmid was cloned and sequenced. The dehalogenase gene (dehH109) was identified by comparison with the N-terminal amino acid sequence and the molecular weight of the enzyme protein. The gene dehH109 coded for a 224-amino acid protein of M(r) 25,231, which showed significant homology to the other four L-specific 2-haloacid dehalogenases from Pseudomonas sp. CBS3, P. putida AJ1, and Xanthobacter autotrophicus GJ10 and also to the haloacetate dehalogenase H-2 from Moraxella sp. strain B, but no homology with another haloacetate dehalogenase H-1 and the D-specific 2-haloacid dehalogenase from P. putida AJ1.

Amino Acid Sequence↗
PubMed1994

Cloning and characterization of a pair of genes that stimulate the production and secretion of Zymomonas mobilis extracellular levansucrase and invertase.

A 1.7-kb DNA fragment cloned from Zymomonas mobilis genomic DNA complemented the inability to grow on sucrose of a Suc- mutant of Z. mobilis that was deficient in the production of both extracellular levansucrase and invertase. Analysis of the nucleotide sequence of the fragment found two open reading frames (ORFs), both of which did not correspond to the structural gene for the levansucrase or the invertase. By subcloning each ORF into two different Suc- mutants of Z. mobilis, it has been found that the first ORF (gene zliE) activates the production of the extracellular levansucrase and invertase, and the second ORF (gene zliS) stimulates the secretion of the two enzymes. Gene zliS might contribute to the secretion of proteins having no signal peptide. The expression of zliE and zliS seemed to be under the control of the same promoter.

Amino Acid Sequence↗
PubMed1993

Purification and characterization of alpha-glucosidase from Torulaspora pretoriensis YK-1.

alpha-Glucosidase was partially purified 103-fold from a cell-free extract of Torulaspora pretoriensis YK-1 by column chromatography on Toyopearl HW55F, DEAE-Toyopearl 650M, hydroxylapatite and phenyl-Toyopearl 650M. Further purification by preparative polyacrylamide gel electrophoresis (PAGE) gave the homogenous protein, but the specific activity was reduced. The molecular weight of the enzyme was estimated to be 69,000 by SDS-PAGE and 60,000 by gel filtration. Optimum pH and temperature were 6.8 and 35 degrees C, respectively. The enzyme was inhibited strongly by AgNO3, HgCl2, sodium dodecyl sulfate, and N-ethylmaleimide. The Km (mM) for p-nitrophenyl alpha-D-glucopyranoside, maltose, maltotriose, isomaltose, methyl alpha-glucoside, and sucrose were 0.15, 150, 45, 17, 18, and 29, and Vmax (mumol/min/mg protein) for those substrates were 87, 0.23, 2.4, 9.0, 12, and 7.4, respectively. The N-terminal amino acid sequence of the enzyme was PEVKNHPETQPKWWKEATVY. The properties of alpha-glucosidase from T. pretoriensis YK-1 were similar to those from Saccharomyces cerevisiae.

Amino Acid Sequence↗
PubMed1992

Lack of homology between two haloacetate dehalogenase genes encoded on a plasmid from Moraxella sp. strain B.

Two genes encoding haloacetate dehalogenases, H-1 and H-2, are closely linked on a plasmid from Moraxella sp. strain B. H-1 predominantly acts on fluoroacetate, but H-2 does not. To elucidate the molecular relationship between the two enzymes, we compared their structural genes. Two restriction fragments of the plasmid DNA were subcloned on M13 phages and their nucleotide sequences were determined. The sequence of each fragment contained an open reading frame that was identified as the structural gene for each of the two dehalogenases on the basis of the following criteria; N-terminal amino acid sequence, amino acid composition, and molecular mass. The genes for H-1 and H-2, designated dehH1 and dehH2, respectively, had different sizes (885 bp and 675 bp) and G+C contents (58.3% and 53.4%). Sequence analysis revealed no homology between the two genes. We concluded that the dehalogenases H-1 and H-2 have no enzyme-evolutionary relationship. The deduced amino acid sequence of the dehH1 gene showed significant similarity to those of three hydrolases of Pseudomonas putida and a haloalkane dehalogenase of Xanthobacter autotrophicus. The dehH2 coding region was sandwiched between two repeated sequences about 1.8 kb long, which might play a part in the frequent spontaneous deletion of dehH2 from the plasmid.

Amino Acid Sequence↗
PubMed1991

Cloning, sequencing, and characterization of the intracellular invertase gene from Zymomonas mobilis.

The structural gene for the intracellular invertase E1 of Zymomonas mobilis strain Z6C was cloned in a 2.25-kb DNA fragment on pUSH11, and expressed in Escherichia coli HB101. The enzyme produced by the E. coli carrying pUSH11 was purified about 1,122 fold to homogenicity with a yield of 4%. The molecular weight and substrate specificity of the enzyme were identical with those of the intracellular invertase E1 from Z. mobilis. The nucleotides of the cloned DNA were sequenced; they included an open reading frame of 1,536 bp, coding for a protein with a molecular weight of 58,728. The N-terminal amino acid sequence predicted was identical with the sequence of the first 20 N-terminal amino acid residues of the protein obtained by Edman degradation. Comparison of the predicted amino acid sequence of E1 protein with those of the four other known beta-D-fructofuranosidases from Escherichia coli, Bacillus subtilis, and Saccharomyces cerevisiae indicated a stronger homology in the N-terminal portion than in the C-terminal portion.

Amino Acid Sequence↗