共查询到19条相似文献,搜索用时 78 毫秒
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旨在通过现代分子生物学技术制备水稻白叶枯病菌FtsZ蛋白。以水稻白叶枯病菌总DNA为模板,采用巢式PCR方法扩增获得水稻白叶枯病菌fts Z基因,构建fts Z基因的表达载体p ET-22b-ftsZ,转化表达宿主E.coli BL21后,经PCR、Nde I/Xho I双酶切及测序鉴定、阳性克隆子经IPTG诱导表达,融合蛋白经镍柱纯化后,通过SDS-PAGE和Western blotting分析鉴定。结果显示,水稻白叶枯病菌ftsZ基因的重组表达载体构建成功,且阳性克隆子在IPTG的诱导下表达了Fts Z-6×His融合蛋白,并通过镍柱纯化获得了电泳纯的Fts Z-6×His融合蛋白。 相似文献
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叶绿体增殖调控机制研究进展 总被引:1,自引:0,他引:1
叶绿体为内共生起源的细胞器。利用电镜观察发现叶绿体分裂时具有中央缢缩现象,并且缢缩过程中存在环状结构。在大肠杆菌中,FtsZ蛋白最早在分裂位点组成一个环状结构(Z-环,FtsZ protein ring),其他分裂相关蛋白再与之结合,共同组成一个复杂的分裂装置,最终导致原核细胞分裂的完成。其分裂位点的选择受到min操纵子(包括MinC,MinD。MinE基因)的精细调控。叶绿体分裂的分子调控机制与原核细胞类似。原核起源与真核起源的分裂相关蛋白组成分裂复合体,确保叶绿体的正常分裂。 相似文献
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在植物叶肉细胞的脱分化、再分化过程中伴随着叶绿体与质体相互转化的过程。已高度分化的叶肉细胞脱分化为分生状态细胞时.其中的原质体主要由叶绿体出芽生殖产生.偶尔可以看到某些叶绿体分裂或分裂与出芽同时出现的情况。此外,叶绿体在出芽产生原质体的同时自身逐渐被巨大的淀粉粒所充满.从而转变为淀粉体。 相似文献
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神经内科与神经外科抗菌药物使用与细菌耐药的比较 总被引:1,自引:0,他引:1
目的 比较神经内科与神经外科抗菌药物使用与细菌耐药情况.方法 计算各类抗菌药物的累积每日约定剂量(defined daily doses,DDD),以及院内感染主要病原菌的耐药率.结果神经内科的抗菌药物总用量为47.83 DDD/100床日,神经外科为78.91 DDD/100床日.神经外科院内感染的凝固酶阴性葡萄球菌、肠球菌和大肠埃希菌对抗菌药物的耐药率普遍较神经内科为高.结论 在抗菌药物使用与细菌耐药水平之间存在着一种联系. 相似文献
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高等植物质体的分裂 总被引:3,自引:0,他引:3
质体来源于早期具光合能力的原核生物与原始真核生物的内共生事件。原核起源的蛋白以及真核寄主起源的蛋白共同参与了质体的分裂过程。以原核生物的细胞分裂蛋白为蓝本, 近些年在植物中陆续鉴定出几种主要的原核生物细胞分裂蛋白的同源物, 如FtsZ、MinD和MinE蛋白。然而, 除此之外, 原核细胞大多数分裂相关因子在植物中找不到其同源物, 但却鉴定了许多真核寄主来源的分裂相关蛋白。当前研究的重点是剖析各种质体分裂蛋白协同作用的机制, 业已证明MinD和MinE的协同作用保证了FtsZ(Z)环的正确定位。尽管经典的FtsZ的抑制因子MinC在植物中不存在, 但实验表明ARC3在拟南芥中具有类似MinC的功能。ARC3蛋白与真核起源的蛋白如ARC5、ARTEMIS、FZL和PD环以及其它原核起源的蛋白如ARC6和GC1等共同构成了一个复杂的植物质体分裂调控系统。 相似文献
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质体来源于早期具光合能力的原核生物与原始真核生物的内共生事件。原核起源的蛋白以及真核寄主起源的蛋白共同参与了质体的分裂过程。以原核生物的细胞分裂蛋白为蓝本,近些年在植物中陆续鉴定出几种主要的原核生物细胞分裂蛋白的同源物,如FtsZ、MinD和MinE蛋白。然而,除此之外,原核细胞大多数分裂相关因子在植物中找不到其同源物,但却鉴定了许多真核寄主来源的分裂相关蛋白。当前研究的重点是剖析各种质体分裂蛋白协同作用的机制,业已证明MinD和Mine的协同作用保证了FtsZ(Z)环的正确定位。尽管经典的FtsZ的抑制因子MinC在植物中不存在,但实验表明ARC3在拟南芥中具有类似MinC的功能。ARC3蛋白与真核起源的蛋白如ARC5、ARTEMIS、FZL和PD环以及其它原核起源的蛋白如ARC6和GC1等共同构成了一个复杂的植物质体分裂调控系统。 相似文献
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【目的】探索大肠埃希氏菌(Escherichia coli,E.coli)FtsZ(236-245)结构域两性螺旋特性对FtsZ组装和FtsZ-FtsA相互作用的影响。【方法】利用分子克隆和定点突变技术,构建FtsZ及其突变体表达载体,亲和纯化获得相应目标蛋白;通过同源重组和Pl转导构建QN23-QN29菌株;利用活细胞成像观察FtsZ及其突变体的胞内定位特点;膜蛋白分离和Western blot分析FtsZ突变体的膜结合特性变化;非变性胶分离和体外聚合分析检测定点突变对FtsZ单体组装特性的影响;免疫沉淀和Far Western blot实验检测FtsZ/FtsZ~*-FtsA间的相互作用。【结果】FtsZ~(E234A/K)和FtsZ~(E241A/K)突变体的功能活性降低、备突变体在E.coli内不能正确定位和形成功能性Z环;E237A/K和E241A/K位点突变致备突变体聚合能力降低、FtsZ*-FtsA的相互作用减弱和FtsZ的膜结合特性变化。【结论】E237和E241是影响FtsZ(236-245)区域两性螺旋特性和FtsZ组装及FtsZ-FtsA相互作用的重要氨基酸。 相似文献
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《Bioorganic & medicinal chemistry》2016,24(24):6354-6369
With the emergence of multidrug-resistant bacterial strains, there is a dire need for new drug targets for antibacterial drug discovery and development. Filamentous temperature sensitive protein Z (FtsZ), is a GTP-dependent prokaryotic cell division protein, sharing less than 10% sequence identity with the eukaryotic cell division protein, tubulin. FtsZ forms a dynamic Z-ring in the middle of the cell, leading to septation and subsequent cell division. Inhibition of the Z-ring blocks cell division, thus making FtsZ a highly attractive target. Various groups have been working on natural products and synthetic small molecules as inhibitors of FtsZ. This review summarizes the recent advances in the development of FtsZ inhibitors, focusing on those in the last 5 years, but also includes significant findings in previous years. 相似文献
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Siti Ma Chao Cong Xiaohui Meng Shasha Cao Hongkun Yang Yuanyuan Guo Xueyi Lu Shutao Ma 《Bioorganic & medicinal chemistry letters》2013,23(14):4076-4079
Novel 3-elongated arylalkoxybenzamide derivatives were designed, synthesized and evaluated for their cell division inhibitory activity and antibacterial activity. Among them, the subseries of 3-alkyloxybenzamide derivatives exhibited greatly improved on-target activity against Bacillus subtilis and Staphylococcus aureus, and remarkably increased antibacterial activity against B. subtilis ATCC9372, penicillin-susceptible S. aureus ATCC25923, methicillin-resistant S. aureus ATCC29213 (MRSA) and penicillin-resistant S. aureus PR compared with 3-methoxybenzamide. In contrast, the subseries of 3-phenoxyaklyloxybenzamide, 3-heteroarylalkyloxybenzamide and 3-heteroarylthioalkyloxybenzamide derivatives only showed a significant improvement in on-target activity and antibacterial activity against B. subtilis ATCC9372. 相似文献
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FtsZ, a prokaryotic homolog of eukaryotic tubulin, is a major constituent of the bacterial Z-ring, which contracts the cell wall during cell division. Because the mechanical properties of FtsZ are unknown, its function in the maintenance and constriction of the Z-ring is not well understood. Here, quantitative rheometry shows that, at physiological concentrations, FtsZ filaments form, extremely rapidly, highly elastic networks within physiological time scales ( approximately minutes), much faster than other major dynamic cytoskeletal filaments, including microtubule, actin, and vimentin in eukaryotes. FtsZ networks display a relatively low viscosity and a high resilience against shear stresses, as well as an elasticity that depends weakly on concentration, G approximately C(0.57), a power-law dependence consistent with crosslinked flexible filaments. Calcium, whose intracellular concentration increases during bacterial division, further enhances the elasticity of FtsZ networks through filament bundling, an effect that occurs in the presence of GTP, not GDP. These studies suggest that FtsZ filaments have the toughness to provide strong mechanical support for the maintenance and circumferential constriction of the bacterial Z-ring. 相似文献
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Srinivasan R Rajeswari H Bhatt BN Indi S Ajitkumar P 《Biochemical and biophysical research communications》2007,357(1):38-43
Factors contributing to the stability of bacterial cell division protein FtsZ remain unknown. In order to identify FtsZ-stabilizing factor(s), we exploited FtsH protease-based in vitro FtsZ degradation assay system. Whole cell lysate from an ftsH-null strain of Escherichia coli inhibited degradation of FtsZ by FtsH in vitro. However, activated charcoal-treated lysate did not inhibit degradation. The loss of ability of the activated charcoal-treated lysate to inhibit degradation of FtsZ was restored when it was replenished with GTP, but not when replenished with other NTPs or dNTPs. The lysate did not protect either FtsZ deletion mutants, which do not bind GTP, or FtsH substrates, sigma(32) and cI-108 proteins, against FtsH. GDP and GTPgammaS also stabilized FtsZ against FtsH. Neither GTP nor GDP inhibited proteolytic activity of FtsH per se. These observations demonstrate that binding of GTP/GDP ligands is responsible for the proteolytic stability of FtsZ against FtsH. 相似文献
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Assembly of the tubulin-like protein FtsZ at or near the cytoplasmic membrane is one of the earliest steps in division of bacteria such as Escherichia coli. Exactly what constitutes the site at which FtsZ acts is less clear. To investigate the influence of the membrane phospholipids on FtsZ localization and assembly, we have elaborated with the Langmuir technique a two-lipid monolayer made of dilauryl-phosphatidylethanolamine (DLPE) and dipalmitoyl-phosphatidylglycerol (DPPG). This monolayer comprised stable condensed domains in an expanded continuous phase. In the presence of GTP, FtsZ assembly disrupts the condensed domains within 5 min. After several hours, with or without GTP, FtsZ assembled into large aggregates at the domain interface. We suggest that the GTP-induced polymerization of FtsZ is coupled to the association of FtsZ protofilaments with domain interfaces. 相似文献
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Mitochondrial fission requires the division of both the inner and outer mitochondrial membranes. Dynamin-related proteins operate in division of the outer membrane of probably all mitochondria, and also that of chloroplasts--organelles that have a bacterial origin like mitochondria. How the inner mitochondrial membrane divides is less well established. Homologues of the major bacterial division protein, FtsZ, are known to reside inside mitochondria of the chromophyte alga Mallomonas, a red alga, and the slime mould Dictyostelium discoideum, where these proteins are likely to act in division of the organelle. Mitochondrial FtsZ is, however, absent from the genomes of higher eukaryotes (animals, fungi, and plants), even though FtsZs are known to be essential for the division of probably all chloroplasts. To begin to understand why higher eukaryotes have lost mitochondrial FtsZ, we have sampled various diverse protists to determine which groups have retained the gene. Database searches and degenerate PCR uncovered genes for likely mitochondrial FtsZs from the glaucocystophyte Cyanophora paradoxa, the oomycete Phytophthora infestans, two haptophyte algae, and two diatoms--one being Thalassiosira pseudonana, the draft genome of which is now available. From Thalassiosira we also identified two chloroplast FtsZs, one of which appears to be undergoing a C-terminal shortening that may be common to many organellar FtsZs. Our data indicate that many protists still employ the FtsZ-based ancestral mitochondrial division mechanism, and that mitochondrial FtsZ has been lost numerous times in the evolution of eukaryotes. 相似文献
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Ito H Ura A Oyamada Y Tanitame A Yoshida H Yamada S Wachi M Yamagishi J 《Microbiology and immunology》2006,50(10):759-764
Out of 95,000 commercially available chemical compounds screened by the anucleate cell blue assay, 138 selected hit compounds were further screened. As a result, A189, a 4-aminofurazan derivative was found to inhibit FtsZ GTPase with an IC(50) of 80 mug/ml and to exhibit antibacterial activity against Staphylococcus aureus and Escherichia coli. Light scattering demonstrated that A189 inhibited FtsZ assembly in vitro, and microscopic observation of A189-treated E. coli indicated that A189 perturbed FtsZ ring formation and made bacterial cells filamentous. However, nucleoids staining with DAPI revealed that A189 did not affect DNA replication and chromosome segregation in bacterial filamentous cells. Furthermore, A189 made sulA-deleted E. coli cells filamentous. Taken together, these findings suggest that A189 inhibits FtsZ GTPase activity, resulting in perturbation of FtsZ ring formation, which leads to bacterial cell death. 相似文献
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FtsZ是与真核微管蛋白类似的原核骨架蛋白,能在细胞分裂位点聚合组装成环状结构而调控细胞分裂过程。为了研究钝顶螺旋藻(Spirulina platensis)FtsZ蛋白的功能,构建了钝顶螺旋藻FtsZ与绿色荧光蛋白GFP融合表达的质粒,并在大肠杆菌中进行了表达和定位研究,结果发现,表达融合蛋白GFP-FtsZ的大肠杆菌细胞由短杆状变为长丝状,且菌丝体长度与融合蛋白的表达量呈正比。在荧光显微镜下观察到融合蛋白GFP-FtsZ在长丝状体细菌中呈有规律的点状分布,这说明FtsZ蛋白功能高度保守,钝顶螺旋藻FtsZ蛋白能识别大肠杆菌分裂位点并装配成环状结构调控大肠杆菌细胞分裂,FtsZ蛋白的过量表达能抑制大肠杆菌正常的细胞分裂而导致长丝状体细胞的形成。 相似文献
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Senyuan Cai Wenchang Yuan Ying Li Xuanhe Huang Qi Guo Ziwei Tang Zhiyuan Fang Hai Lin Wing-Leung Wong Kwok-Yin Wong Yu-Jing Lu Ning Sun 《Bioorganic & medicinal chemistry》2019,27(7):1274-1282
Filamenting temperature-sensitive mutant Z (FtsZ) is recognized as a promising target for new antibiotics development because of its high conservatism and pivotal role in the bacteria cell division. The aromatic heterocyclic scaffold of indole is known showing merit medical functions in antiviral and antimicrobial. In the present study, a series of 1-methylquinolinium derivatives, which were integrated with an indole fragment at its 2-position and a variety of amino groups (cyclic or linear, mono- or di-amine) at the 4-position were synthesized and their antibacterial activities were evaluated. The results of antibacterial study show that the representative compounds can effectively inhibit the growth of testing strains including MRSA and VRE, with MIC values of 1–4?μg/mL by bactericidal mode. The mode of action assays revealed that c2 can effectively disrupt the rate of GTP hydrolysis and dynamic polymerization of FtsZ, and thus inhibits bacterial cell division and then causes bacterial cell death. In addition, the result of resistance generation experiment reveals that c2 is not likely to induce resistance in S. aureus. 相似文献