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Y Sadaie

Publications and source records attributed to Y Sadaie.

At least 37 records · Page 2Linked to original sources
PubMed1991

Sequencing reveals similarity of the wild-type div+ gene of Bacillus subtilis to the Escherichia coli secA gene.

We have determined the nucleotide (nt) sequence of the wild-type div+ gene of Bacillus subtilis which complements the temperature-sensitive div-341 mutation and is involved in cell septation, sporulation, secretion of extracellular enzymes, development of competence, autolysis and spore outgrowth. It has an open reading frame encoding 841 amino acids (aa) with homology to the Escherichia coli secA gene, which is involved in protein secretion and cell separation. The deduced aa sequence of the B. subtilis div+ gene shares 50% identity with that of the E. coli secA gene, and highly homologous regions were observed in the N-terminal portions. DNA-DNA hybridization with the E. coli secA gene as the probe showed that the div+ gene could be easily detected by homology and that a single copy of the homologous gene was present in B. subtilis. Since both genes are similar in their functions and deduced aa sequences, we propose that the div+ gene is the counterpart of the secA gene of E. coli.

Amino Acid Sequence↗
PubMed1989

Rad-2-dependent repair of radiation-induced chromosomal aberrations in Caenorhabditis elegans.

A method involving light microscopy was developed and utilized for the observation of gamma- or ultraviolet-induced aberrations of the chromosomes of Caenorhabditis elegans var. Bristol (N2). Gravid worms were irradiated and the chromosomes were examined in the early embryos derived from eggs fertilized after the irradiation. The frequency of gamma-induced aberrations in the early embryonic cells of C. elegans increased proportionally with the dosage of gamma-rays. It decreased greatly following incubation of the irradiated gravid worms for 2 days. This decrease was blocked by the rad-2 mutation but not by the rad-1 mutation of the same epistasis group. Both mutations make worms sensitive to radiation and chemicals. In addition, the hatchability of eggs laid by the rad-2 mutant after irradiation was restored very quickly as was that of the wild-type strain. Ultraviolet irradiation, on the other hand, induced few aberrations in both the wild-type and rad-1 strains, but it caused an elevated frequency of aberrations in the rad-2 strain. Ultraviolet irradiation strongly blocked the separation of chromosomes of the rad-2 strain. Furthermore, hatchability was very low in eggs laid by ultraviolet-irradiated rad-2 worms. These results suggest the existence of a rad-2-dependent mechanism for gonadal repair of chromosomal aberrations, including chromosomal non-separation, and indicate that gamma-induced chromosome aberrations are not fatal to the hatching of Caenorhabditis elegans which has holocentric chromosomes.

Animals↗
PubMed1989

Molecular cloning of a Bacillus subtilis gene involved in cell division, sporulation, and exoenzyme secretion.

The wild type div-341+ gene of Bacillus subtilis was cloned in a temperate phage rho 11, and was recloned in a smaller temperate phage phi 105. The resulting Div+ transducing phage carried a 3 kilobase Cfr13I digested chromosomal fragment which showed Div+ transforming activity and contained the whole div-341+ gene which is involved in cell division, sporulation, exoenzyme secretion, competent cell formation, and autolysis. A partial restriction map of the fragment was established. The merodiploid system of the div-341+ gene, wild type gene on the phage genome and mutant gene on the chromosome, resulted in the suppression of mutant phenotypes and indicated that the wild type div-341+ gene is dominant over mutant gene.

Bacillus subtilis↗
PubMed1985

Bacillus subtilis gene involved in cell division, sporulation, and exoenzyme secretion.

Bacillus subtilis strains carrying div-341 or sacU mutations, or both, have been characterized to reveal the roles of both genes in the initiation of sporulation, as well as in cell division and exoenzyme secretion. Both mutations were closely linked by transformation and caused the pleiotropic effects on sporulation and sporulation-associated events. Some sacU mutations (sacUh) resulted in hyperproduction of exoenzymes, reduced autolysis, and an ability to sporulate in the presence of excess nutrients. The div-341 mutation, on the other hand, resulted in filamentous growth at a higher temperature (45 degrees C) and showed spo0 properties at an intermediate permissive temperature (37 degrees C) in the usual sporulation medium. However, the div-341 strain sporulated better than wild-type strain at 37 degrees C in the presence of excess nutrients. Exoenzyme production and autolysis were reduced at 37 degrees C in the div-341 strain. A double mutant with sacUh32 and div-341 showed the complex phenotypes. It showed the sacUh32 property of autolysis and exoenyzme secretion. It showed the sacUh32 property of sporulation at 30 degrees C and the div-341 property at 37 degrees C. Slow growth and defective spore outgrowth of the div-341 strain at 37 degrees C were not observed in the double-mutant strain. Based on pleiotropic phenotypes and close linkages of both mutations, we discuss the relationship between the sacU and div-341 genes and their roles in sporulation, exoenzyme secretion, and cell division.

Bacillus subtilis↗
PubMed1983

Formation of competent Bacillus subtilis cells.

The process of competent cell formation for transformation has been studied with early-stationary-phase (T1) cells of Bacillus subtilis which had been grown in an enriched Spizizen minimal medium and transferred to a second synthetic medium. Rifampin, chloramphenicol, and tunicamycin were strong inhibitors of competent cell formation, as well as vegetative growth. After formation, competent cells were no longer sensitive to the above agents. Methicillin and an inhibitor of chromosomal replication, hydroxyphenylazouracil, did not inhibit the development of competence. A D-alanine-requiring mutant strain developed competence even in the absence of D-alanine in the second medium. A T1-stage culture showed the activity of extracellular serine protease which is necessary for sporulation. Competent cell formation was completely blocked by 0.7 M ethanol, which is a specific inhibitor of early events during sporulation, including forespore septum formation. Competent cells were formed even in media which supported sporulation. The development of competence was also studied with spo0 mutants at 10 different loci. Most spo0 mutations repressed the development of competence except for spo0C, spo0G, and spo0J. These results suggest that competent cells are formed from early sporulating cells with the synthesis of cell wall materials and by factors whose genes are activated by the supply of nutrients. It is suggested that common steps are involved both in forespore septation and in competent cell formation.

Alanine↗
PubMed1983

DNA repair in competent cells of Bacillus subtilis.

A series of isogenic transformable strains of Bacillus subtilis carrying the uvr-19 or rec-43 mutation or both were constructed. Both mutations made competent cells defective in repairing UV-irradiated cellular or transforming DNA, and their effects were additive in a doubly deficient strain, suggesting that two repair processes, requiring uvr-19+ and rec-43+ gene products, are independently functional in competent cells of B. subtilis.

Bacillus subtilis↗
PubMed1980

Purification and characterization of a kanamycin nucleotidyltransferase from plasmid pUB110-carrying cells of Bacillus subtilis.

The nucleotidyltransferase encoded by plasmid pUB110 was purified to greater than 95% purity with a 33% yield. The enzyme is a monomeric protein with a molecular weight of 34,000. The optimum pH for activity is 5, and the optimum MgCl2 concentration for activity is 18 mM. The enzyme, which is synthesized constitutively, is stable for several weeks at 4 degrees C. This enzyme would appear to be a good model gene product for the development of a pUB110 deoxyribonucleic acid-dependent in vitro protein-synthesizing system from Bacillus subtilis.

Bacillus subtilis↗
PubMed1978

Spore coat protein of Bacillus subtilis. Structure and precursor synthesis.

The coat protein of Bacillus subtilis spores comprises about 10% of the total dry weight of spores and 25% of the total spore protein. One protein with a molecular weight of 13,000 to 15,000 comprises a major portion of the spore coat. This mature spore coat protein has histidine at its NH2 terminus and is relatively rich in hydrophobic amino acids. Netropsin, and antibiotic which binds to A-T-rich regions of DNA and inhibits sporulation, but not growth, decreased the synthesis of this spore coat protein by 75%. A precursor spore coat protein with a molecular weight of 25,000 is made initially at t1 of sporulation and is converted to the mature spore coat protein with a molecular weight of 13,500 at t2 - t3. These data indicate that the spore coat protein gene is expressed very early in sporulation prior to the modifications of RNA polymerase which have been noted.

Amino Acids↗
PubMed1978

Spore coat protein synthesis in cell-free systems from sporulating cells of Bacillus subtilis.

Cell-free systems for protein synthesis were prepared from Bacillus subtilis 168 cells at several stages of sporulation. Immunological methods were used to determine whether spore coat protein could be synthesized in the cell-free systems prepared from sporulating cells. Spore coat protein synthesis first occurred in extracts from stage t2 cells. The proportion of spore coat protein to total proteins synthesized in the cell-free systems was 2.4 and 3.9% at stages t2 and t4, respectively. The sodium dodecyl sulfate-urea-polyacrylamide gel electrophoresis patterns of immunoprecipitates from the cell-free systems showed the complete synthesis of an apparent spore coat protein precursor (molecular weight, 25,000). A polypeptide of this weight was previously identified in studies in vivo (L.E. Munoz, Y. Sadaie, and R.H. Doi, J. Biol. Chem., in press). The synthesis in vitro of polysome-associated nascent spore coat polypeptides with varying molecular weights up to 23,000 was also detected. These results indicate that the spore coat protein may be synthesized as a precursor protein. The removal of proteases in the crude extracts by treatment with hemoglobin-Sepharose affinity techniques may be preventing the conversion of the large 25,000-dalton precursor to the 12,500-dalton mature spore coat protein.

Bacillus subtilis↗
PubMed1976

Recombination-deficient mutants of Bacillus subtilis.

Two mutant strains of Bacillus subtilis Marburg, NIG43 and NIG45, were isolated. They showed high sensitivities to gamma rays, ultraviolet light (UV), and chemicals. Deficiencies in genetic recombination of these two mutants were shown by the experiments on their capacity in transformation. SPO2 transfection, and PBS1 phage transduction, as well as on their radiation and drug sensitivities and their Hcr+ capacity for UV-exposed phage M2. Some of these characteristics were compared with those of the known strains possessing the recA1 or recB2 alleles. Mapping studies revealed that the mutation rec-43 of strain NIG43 lies in the region of chromosome replication origin. The order was purA dna-8132 rec-43. Another mutation, rec-45, of strain NIG45 was found to be tightly linked to recA1. The mutation rec-43 reduced mainly the frequency of PBS1 transduction. On the other hand, the mutation rec-45 reduced the frequency of recombination involved both in transformation and PBS1 transduction. The mutation rec-43 of strain NIG43 is conditional, but rec-45 of strain NIG45 is not. The UV impairment in cellular survival of strain NIG43 was gradually reverted at higher salt or sucrose concentrations, suggesting cellular possession of a mutated gene produce whose function is conditional. In contrast to several other recombination-deficient strains, SPO2 lysogens of strain NIG43 and NIG45 were not inducible, indicating involvement of rec-43+ or rec-45+ gene product in the development of SPO2 prophage to a vegetative form. The UV-induced deoxyribonucleic acid degradation in vegetative cells was higher in rec-43 and rec-45 strains.

Bacillus subtilis↗
PubMed1976

Repair deficiency, mutator activity, and thermal prophage inducibility in dna-8132 strains of Bacillus subtilis.

A ts mutation, dna-8132 (Hara and Yoshikawa, 1973), in the region of chromosome replication origin of Bacillus subtilis was found to cause pleiotropic effects at a permissive temperature (30 C). Strains carrying this mutation were lethan at 48 C but exhibited higher spontaneous mutation frequency and a lower capacity for repairing radiation damages at 30C. Introduction of the polA59 (Gass et al., 1971) mutation further enhanced the repair deficiency and the mutator activity. These results suggest that the dna-8132 gene product may be directly involved in chromosome replication and repair. SPO2 lysogens carrying this mutation produced mature phages upon a temperature shift from 30 to 48 C. Phage production at nonpermissive temperature suggests that there are few defects in the precursors of deoxyribonucleic acid synthesis in the mutant.

4-Nitroquinoline-1-oxide↗