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1.
2.
Takashi Yutsudo Hisao Kurazono Chihiro Sasakawa Masanosuke Yoshikawa Makoto Iwaya Tae Takeda Yoshifumi Takeda 《FEMS microbiology letters》1987,48(1-2):273-276
Abstract A Vero toxin (VT2 or Shiga-like toxin II)-converting phage was isolated from Escherichia coli 0157: H7 strain J-2. Nontoxigenic E. coli C600 produced VT2 when lysogenized with the toxin-converting phage. Eco RI fragments of the phage DNA were ligated with Eco RI-digested pBR322 or pUC118 and were transformed into E. coli MC1061 or MV1184. Transformants exhibiting VT2 production commonly contained a 4.6 kb Eco RI fragment. It was found that a 2.3 kb Kpn I- Sph I fragment coded VT2 production and that this fragment hybridized weakly with the 2.1 kb fragment encoding VT1. 相似文献
3.
Junzou Hiratsuka Hiroaki Shimada Robert Whittier Takashi Ishibashi Masahiro Sakamoto Masao Mori Chihiro Kondo Yasuko Honji Chong-Rong Sun Bing-Yuan Meng Yu-Qing Li Akira Kanno Yoko Nishizawa Atsushi Hirai Kazuo Shinozaki Masahiro Sugiura 《Molecular & general genetics : MGG》1989,217(2-3):185-194
Summary The entire chloroplast genome of the monocot rice (Oryza sativa) has been sequenced and comprises 134525 bp. Predicted genes have been identified along with open reading frames (ORFs) conserved
between rice and the previously sequenced chloroplast genomes, a dicot, tobacco (Nicotiana tabacum), and a liverwort (Marchantia polymorpha). The same complement of 30 tRNA and 4 rRNA genes has been conserved between rice and tobacco. Most ORFs extensively conserved
betweenN. tabacum andM. polymorpha are also conserved intact in rice. However, several such ORFs are entirely absent in rice, or present only in severely truncated
form. Structural changes are also apparent in the genome relative to tobacco. The inverted repeats, characteristic of chloroplast
genome structure, have expanded outward to include several genes present only once per genome in tobacco and liverwort and
the large single copy region has undergone a series of inversions which predate the divergence of the cereals. A chimeric
tRNA pseudogene overlaps an apparent endpoint of the largest inversion, and a model invoking illegitimate recombination between
tRNA genes is proposed which accounts simultaneously for the origin of this pseudogene, the large inversion and the creation
of repeated sequences near the inversion endpoints. 相似文献
4.
The molybdenum-iron component of nitrogenase (Mo-Fe component)was purified from soybean nodule bacteroids and antibody wasraised against it in rabbits. Antibody raised against the 53kDa polypeptide which was the major protein in the Mo-Fe componentfraction of soybean nitrogenase was confirmed to be specificto the nitrogenase by immunodiffusion and immunotitration. Thenitrogenase from root nodules of Elaeagnus pungens cross-reactedwith the antibody and appeared from the results of the immunodiffusionto be partially identical to soybean nitrogenase. Using the antibody, we examined intracellular localization ofnitrogenase in root nodules of Elaeagnus pungens, in which Frankiais present as a symbiont, by immuno-gold labelling. Thin sectionsof nodules of Elaeagnus pungens were first treated with anti-nitrogenasespecific antibody and then with colloidal gold-protein A asa marker. The gold particles were observed to be concentratedin the vesicles of the endophyte Frankia. This provides strongsupport for the existence E of nitrogenase in the vesicles.Furthermore, our results suggested that nitrogenase localizesin the hyphae of the endophyte Frankia in Elaeagnus pungensnodules.
1Present address: Iwata Experiment Station, Japan Tobacco Inc.,Iwata-gun, Shizuoka 438, Japan. (Received March 9, 1988; Accepted July 28, 1988) 相似文献
5.
6.
Cloning and CO2 -dependent expression of the genetic region for encapsulation from Bacillus anthracis 总被引:7,自引:1,他引:6
The capsule of Bacillus anthracis is an important virulence factor consisting of poly-D-glutamic acid. The genetic region required for the encapsulation was cloned in Escherichia coli from the capsule plasmid pTE702, using a selection procedure based on an immunodiffusion assay. The cloned region directed synthesis of the capsule both in E. coli and B. anthracis. Capsule synthesis from these clones, as in the wild type, was dependent upon the presence of CO2. However, encapsulation directed by the cloned fragment was less marked than from pTE702. Another region enhancing capsulation was shown to exist on pTE702. The minimum size of the encapsulation region was defined to within 2.7 kb DNA and shown to be essential for the encapsulation in B. anthracis. 相似文献
7.
Dr. Tomonobu Kusano Kazuyuki Sugawara Chihiro Inoue Nobuhiro Suzuki 《Current microbiology》1991,22(1):35-41
The genes coding ford-ribulose-1,5-bisphosphate carboxylase (RuBPCase) from an iron-oxidizing bacterium,Thiobacillus ferrooxidans, were cloned into anEscherichia coli plasmid, pUC18. The recombinant plasmid, termed pTR11, contained a 4.0-kb PstI fragment including the entire coding regions for both large and small subunits of RuBPCase.Escherichia coli carrying pTR11 did not show any CO2-fixing activity. However, a derivative plasmid with an appropriate deletion, which was placed under the control of atac promoter, conferred ribulose bisphosphate-dependent CO2-fixing activity on the host cell. Analysis of gel-filtration chromatography of the RuBPCase synthesized inE. coli revealed that it had a hexadecameric form like the native enzyme ofT. ferrooxidans. 相似文献
8.
Virulence-associated genetic regions comprising 31 kilobases of the 230-kilobase plasmid in Shigella flexneri 2a. 总被引:42,自引:9,他引:33 下载免费PDF全文
C Sasakawa K Kamata T Sakai S Makino M Yamada N Okada M Yoshikawa 《Journal of bacteriology》1988,170(6):2480-2484
By random transposon Tn5 insertions, we previously identified six virulence-associated SalI fragments, B, D, F, G, H, and P, in the 230-kilobase plasmid pMYSH6000 of Shigella flexneri 2a. In this study, we analyzed the sites of 134 independent Tn5 insertions on four contiguous SalI fragments, B, P, H, and D, of pMYSH6000 and identified five virulence-associated regions; four were associated with inducing a positive Sereny test (Ser), invasion into epithelial cells (Inv), binding to Congo red (Pcr), and inhibition of bacterial growth (Igr), and one was associated with the Ser and Inv but not with the Pcr or Igr phenotypes. Hybridization studies revealed that these virulence-associated DNA regions were highly conserved among 15 other virulence plasmids of four species of Shigella and enteroinvasive Escherichia coli. These data indicate that at least seven separate genetic determinants on the virulence plasmid are required for full expression of the virulence phenotype of shigellae. 相似文献
9.
Nobuyuki Sasakawa Konosuke Kumakura Satoshi Yamamoto Ryuichi Kato 《Life sciences》1983,33(20):2017-2024
Effects of N-(6-aminohexyl)-5-chloro-1-naph-thalenesulfonamide (W-7), a calmodulin antagonist, on catecholamine (CA) release and 45Ca2+ uptake were studied using cultured bovine adrenal chromaffin cells. W-7 inhibited the carbamylcholine (CCh)-evoked CA release and 45Ca2+ uptake in a concentration-dependent manner. The inhibitory effect of W-7 on CCh-evoked CA release was not overcome either by an increase in extracellular calcium or CCh concentration. Although W-7 inhibited the high K+-evoked CA release and 45Ca2+ uptake, potency of the drug was approximately 50–100 fold less than when inhibiting the CCh-evoked CA release and 45Ca2+ uptake. The inhibitory effects of W-7 were observed both in norepinephrine release and epinephrine release. Moreover, W-7 inhibited the CCh-evoked 45Ca2+ efflux. These results suggest that the inhibition of CA release by W-7 in adrenal chromaffin cells is mainly due to its inhibition of calcium uptake. W-7 may influence the linkage between acetylcholine-receptor and calcium uptake with higher potency than depolarization-dependent calcium entry. 相似文献
10.
When [3H]inositol prelabelled cultured bovine adrenal chromaffin cells were stimulated with 56 mM KCl (high K+), 300 microM carbamylcholine (CCh) or 10 microM angiotensin II (Ang II), a rapid accumulation of [3H]IP3 was observed. At the same time, high K+ or CCh induced rapid increases in 45Ca2+ uptake, but Ang II did not induce a significant 45Ca2+ uptake. The concentration-response curve for KCl-induced [3H]IP3 accumulation coincided well with that for KCl-induced 45Ca2+ uptake into the cells. Nifedipine, a Ca2+ channel antagonist, inhibited the high K(+)-induced [3H]IP3 accumulation and 45Ca2+ uptake with a similar potency. Nifedipine at a similar concentration range also inhibited CCh-induced 45Ca2+ uptake. Although nifedipine inhibited CCh-induced [3H]IP3 accumulation, the potency was approximately 300-fold less than that for the inhibition of 45Ca2+ uptake. Nifedipine failed to affect the Ang II-induced [3H]IP3 accumulation. BAY K 8644 (2 microM), a Ca2+ channel activator, plus partially depolarizing concentration of KCl (14 mM), induced 45Ca2+ uptake and [3H]IP3 accumulation. Ionomycin (1 microM and 10 microM), a Ca2+ ionophore, also induced 45Ca2+ uptake and [3H]IP3 accumulation in a concentration-dependent manner. Pretreatment of the cells with protein kinase C activator, 100 nM 12-O-tetradecanoyl phorbol-13-acetate, for 10 min, partially inhibited CCh and Ang II-induced [3H]IP3 accumulation, but failed to inhibit the high K(+)-induced accumulation. Furthermore, the effects of high K+ and Ang II on the IP3 accumulation was additive. Ang II and CCh induced a rapid and transient increase in inositol 1,4,5-trisphosphate (1,4,5-IP3) accumulation (5 s) followed by a slower accumulation of inositol 1,3,4-trisphosphate (1,3,4-IP3). High K+ evoked an increase in 1,3,4-IP3 accumulation but obvious accumulation of 1,4,5-IP3 could not be detected. In Ca2(+)-depleted medium, high K(+)-induced [3H]IP3 accumulation was completely abolished, whereas [3H]IP3 accumulation induced by CCh and Ang II was partially inhibited. These results demonstrate the existence of the Ca2+ uptake-triggered mechanism of IP3 accumulation represented by high K+, and also the Ca2+ uptake-independent mechanism of IP3 accumulation represented by Ang II in cultured bovine adrenal chromaffin cells. Mechanism of CCh-induced IP3 accumulation has an intermediate property between those of high K+ and Ang II. 相似文献