992 resultados para Accession number


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Metabolomic analysis has shown the chemical richness of the sponge-associated actinomycetes Streptomyces sp. SBT349, Nonomureae sp. SBT364, and Nocardiopsis sp. SBT366. The genomes of these actinomycetes were sequenced and the genomic potential for secondary metabolism was evaluated. Their draft genomes have sizes of 8.0, 10, and 5.8Mb having 687, 367, and 179 contigs with a GC content of 71.6, 70.7, and 72.7%, respectively. Moreover, antiSMASH 3.0 predicted 108, 149, and 75 secondary metabolite gene clusters, respectively which highlight the metabolic capacity of the three actinomycete species to produce diverse classes of natural products.

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Here, we report the draft genome sequences of three actinobacterial isolates, Micromonospora sp. RV43, Rubrobacter sp. RV113, and Nocardiopsis sp. RV163 that had previously been isolated from Mediterranean sponges. The draft genomes were analyzed for the presence of gene clusters indicative of secondary metabolism using antiSMASH 3.0 and NapDos pipelines. Our findings demonstrated the chemical richness of sponge-associated actinomycetes and the efficacy of genome mining in exploring the genomic potential of sponge-derived actinomycetes.

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Based on our current knowledge about population genetics, phylogeography and speciation, we begin to understand that the deep sea harbours more species than suggested in the past. Deep-sea soft-sediment environment in particular hosts a diverse and highly endemic invertebrate fauna. Very little is known about evolutionary processes that generate this remarkable species richness, the genetic variability and spatial distribution of deep-sea animals. In this study, phylogeographic patterns and the genetic variability among eight populations of the abundant and widespread deep-sea isopod morphospecies Betamorpha fusiformis [Barnard, K.H., 1920. Contributions to the crustacean fauna of South Africa. 6. Further additions to the list of marine isopods. Annals of the South African Museum 17, 319-438] were examined. A fragment of the mitochondrial 16S rRNA gene of 50 specimens and the complete nuclear 18S rRNA gene of 7 specimens were sequenced. The molecular data reveal high levels of genetic variability of both genes between populations, giving evidence for distinct monophyletic groups of haplotypes with average p-distances ranging from 0.0470 to 0.1440 (d-distances: 0.0592-0.2850) of the 16S rDNA, and 18S rDNA p-distances ranging between 0.0032 and 0.0174 (d-distances: 0.0033-0.0195). Intermediate values are absent. Our results show that widely distributed benthic deep-sea organisms of a homogeneous phenotype can be differentiated into genetically highly divergent populations. Sympatry of some genotypes indicates the existence of cryptic speciation. Flocks of closely related but genetically distinct species probably exist in other widespread benthic deep-sea asellotes and other Peracarida. Based on existing data we hypothesize that many widespread morphospecies are complexes of cryptic biological species (patchwork hypothesis).

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Multiple sclerosis (MS) is a debilitating, chronic demyelinating disease of the central nervous system affecting over 2 million people worldwide. The TAM family of receptor tyrosine kinases (TYRO3, AXL and MERTK) have been implicated as important players during demyelination in both animal models of MS and in the human disease. We therefore conducted an association study to identify single nucleotide polymorphisms (SNPs) within genes encoding the TAM receptors and their ligands associated with MS. Analysis of genotype data from a genome-wide association study which consisted of 1618 MS cases and 3413 healthy controls conducted by the Australia and New Zealand Multiple Sclerosis Genetics Consortium (ANZgene) revealed several SNPs within the MERTK gene (Chromosome 2q14.1, Accession Number NG_011607.1) that showed suggestive association with MS. We therefore interrogated 28 SNPs in MERTK in an independent replication cohort of 1140 MS cases and 1140 healthy controls. We found 12 SNPs that replicated, with 7 SNPs showing p-values of less than 10-5 when the discovery and replication cohorts were combined. All 12 replicated SNPs were in strong linkage disequilibrium with each other. In combination, these data suggest the MERTK gene is a novel risk gene for MS susceptibility. © 2011 Ma et al.

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Documents, medals, and photos pertaining to Max Strauss' service in the German Army before and during World War I:

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We present the complete mitochondrial genome (accession number: LK995454) of an iconic Australian species, the eastern grey kangaroo (Macropus giganteus). The mitogenomic organization is consistent with other marsupials, encoding 13 protein-coding genes, 22 tRNA genes, 2 ribosomal RNA genes, an origin of light strand replication and a control region or Dloop. No repetitive sequences were detected in the control region. The M. giganteus mitogenome exemplifies a combination of tRNA gene order and structural peculiarities that appear to be unique to marsupials. We present a maximum likelihood phylogeny based on complete mitochondrial protein and RNA coding sequences that confirms the phylogenetic position of the grey kangaroo among macropodids.

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The non-oxidative decarboxylation of aromatic acids is a poorly understood reaction. The transformation of 2,3-dihydroxybenzoic acid to catechol in the fungal metabolism of indole is a prototype of such a reaction. 2,3-Dihydroxybenzoic acid decarboxylase (EC 4.1.1.46) which catalyzes this reaction was purified to homogeneity from anthranilate induced cultures of Aspergillus oryzae using affinity chromatography. The enzyme did not require cofactors like NAD(+), PLP, TPP or metal ions for its activity. There was no spectral evidence for the presence of enzyme bound cofactors. The preparation, which was adjudged homogeneous by the criteria of SDS-PAGE, sedimentation analysis and N-terminal analysis, was characterized for its physicochemical and kinetic parameters. The enzyme was inactivated by group-specific modifiers like diethyl pyrocarbonate (DEPC) and N-ethylmaleimide (NEM). The kinetics of inactivation by DEPC suggested the presence of a single class of essential histidine residues, the second order rate constant of inactivation for which was 12.5 M(-1) min(-1). A single class of cysteine residues was modified by NEM with a second order rate constant of 33 M(-1) min(-1). Substrate analogues protected the enzyme against inactivation by both DEPC and NEM, suggesting the Location of the essential histidine and cysteine to be at the active site of the enzyme. The incorporation of radiolabelled NEM in a differential labelling experiment was 0.73 mol per mol subunit confirming the presence of a single essential cysteine per active-site. Differentially labelled enzyme was enzymatically cleaved and the peptide bearing the label was purified and sequenced. The active-site peptide LLGLAETCK and the N-terminal sequence MLGKIALEEAFALPRFEEKT did not bear any similarity to sequences reported in the Swiss-Prot Protein Sequence Databank, a reflection probably of the unique primary structure of this novel enzyme. The sequences reported in this study will appear in the Swiss-Prot Protein Sequence Databank under the accession number P80402.

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Cytosolic nucleotidase II (cN-II) from Legionellapneumophila (Lp) catalyzes the hydrolysis of GMP and dGMP displaying sigmoidal curves, whereas catalysis of IMP hydrolysis displayed a biphasic curve in the initial rate versus substrate concentration plots. Allosteric modulators of mammalian cN-II did not activate LpcN-II although GTP, GDP and the substrate GMP were specific activators. Crystal structures of the tetrameric LpcN-II revealed an activator-binding site at the dimer interface. A double mutation in this allosteric-binding site abolished activation, confirming the structural observations. The substrate GMP acting as an activator, partitioning between the allosteric and active site, is the basis for the sigmoidicity of the initial velocity versus GMP concentration plot. The LpcN-II tetramer showed differences in subunit organization upon activator binding that are absent in the activator-bound human cN-II structure. This is the first observation of a structural change induced by activator binding in cN-II that may be the molecular mechanism for enzyme activation. DatabaseThe coordinates and structure factors reported in this paper have been submitted to the Protein Data Bank under the accession numbers and . The accession number of GMP complexed LpcN-II is . Structured digital abstract andby() andby() Structured digital abstract was added on 5 March 2014 after original online publication]

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Endophytic fungi isolated from Catharanthus roseus were screened for the production of vincristine and vinblastine. Twenty-two endophytic fungi isolated from various tissues of C. roseus were characterized taxonomically by sequence analysis of the internal transcribed spacer (ITS) region of rDNA and grouped into 10 genera: Alternaria, Aspergillus, Chaetomium, Colletotrichum, Dothideomycetes, Eutypella, Eutypa, Flavodon, Fusarium and Talaromyces. The antiproliferative activity of these fungi was assayed in HeLa cells using the MTT assay. The fungal isolates Eutypella sp-CrP14, obtained from stem tissues, and Talaromyces radicus-CrP20, obtained from leaf tissues, showed the strongest antiproliferative activity, with IC50 values of 13.5 mu g/ml and 20 mu g/ml, respectively. All 22 endophytic fungi were screened for the presence of the gene encoding tryptophan decarboxylase (TDC), the key enzyme in the terpenoid indole alkaloid biosynthetic pathway, though this gene could only be amplified from T. radicus-CrP20 (NCBI GenBank accession number KC920846). The production of vincristine and vinblastine by T. radicus-CrP20 was confirmed and optimized in nine different liquid media. Good yields of vincristine (670 mu g/l) in modified M2 medium and of vinblastine (70 mu g/l) in potato dextrose broth medium were obtained. The cytotoxic activity of partially purified fungal vincristine was evaluated in different human cancer cell lines, with HeLa cells showing maximum susceptibility. The apoptosis-inducing activity of vincristine derived from this fungus was established through cell cycle analysis, loss of mitochondrial membrane potential and DNA fragmentation patterns.

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脂肪酸是生物体内普遍存在、具重要生理功能的物质,亦是重要的化工原料。研究脂肪酸生物合成及其调控,既是揭示生命活动基本规律的需要,又具巨大的经济价值。多形汉逊氏酵母(Hansenula polymorpha)是一种甲基嗜热酵母,能合成多聚不饱和脂肪酸,是研究脂肪酸生物合成的理想材料之一。为阐明多形汉逊氏酵母细胞中脂肪酸生物合成途径、关键步骤、调节机理,并利用此系统生产有用脂肪酸,我们开展了不饱和脂肪酸生物合成关键酶基因--△9-脂肪酸去饱和酶基因研究。 以P. angusta IFO 1475的P-OLE1基因为探针,Southern杂交分析,发现在亲缘关系很近的不同种类的甲基嗜热酵母如H. pofymorpha、Pichia angusta、P. pastoris、P. methanolica和Candida boMinii中Δ9-脂肪酸去饱和酶基因的结构多形性。 构建了H. polymorpha CBS 1976染色体Δ9-脂肪酸去饱和酶基因座位的限制性酶切图谱,进而分离了3.4 kb BamHI-XhoI基因片段并进行全序列分析,结果表明这个片段含1个与已克隆的酵母Δ59-脂肪酸去饱和酶基因高度同源的、由1353 bp组成的ORF。推导的H-OLE1多肽具脂肪酸去饱和酶的一些基本特征,如含2个结构域:1个位于N一端、含3个保守的组氨酸簇、具催化功能,另1个位于C-端、参与脱饱和反应中电子传递、类似细胞色素b5。将这个序列申报DDBJ,获得Accession number为:AB024576,推导的蛋白的氨基酸序列的Accession number为:BAA75902。 为验证H-OLE1基因的功能,建立了多形汉逊氏酵母DNA电穿孔实验系统,进行了遗传互补测验。发现完整的H-OLE1基因可互补缺乏Δ59-脂肪酸去饱和酶活性的多形汉逊氏酵母营养缺陷型fadl突变体,却不能互补相应的酿酒酵母olel突变体,而由酿酒酵母GAP表达框架和H-OLE1 ORF组成的嵌合基因可互补上述olel突变体。说明H-OLE1基因编码Δ9-脂肪酸去饱和酶,多形汉逊氏酵母的Δ9-脂肪酸去饱和酶和酿酒酵母的脂肪酸脱饱和系统相亲和,而H-OLE1基因的启动子在异源细胞中没有活性。 为研究H-OLE1基因的转录及其调节规律,通过一系列实验,首次找到了可在研究多形汉逊氏酵母基因表达时用作内标的GAP基因。Northern杂交发现,H-OLE1基因在细胞中以较低水平表达,产生1.5 kb的转录子;基因表达略受不饱和脂肪酸的抑制;在多形汉逊氏酵母HOLE1基因的转录调节中,Choi等在酿酒酵母OLE1基因中发现的脂肪酸调节元件FAR可能不是关键的。 利用基因敲除技术,通过转化H-OLE1∷S-LEU2线性DNA到多形汉逊氏酵母二倍体细胞(fadl/FADl)中,首次构建了多形汉逊氏酵母H-OLE1基因的破坏株。遗传学和分子生物学研究表明,破坏株细胞中线性DNA定位串联多拷贝整合到染色体中并置换了fadl突变部位。利用气相色谱分析了ΔH-OLE1破坏株、fadl-2突变株、野生型菌株及含H-OLE1基因转化子的细胞总脂肪酸,发现多形汉逊氏酵母细胞中除18:0→18:1(Δ9)→18:2(Δ9,12)→18:3(Δ9,12,15)这个脂肪酸去饱和主路外,还可能存在其它几个脱饱和反应与延长反应,如16:1(Δ9)→16:2(Δ9,12)→18:2(Δ11,14);16:1(Δ9)→18:1(Δ11)→18:2(Δ11,15)等。 近年维管组织分化研究进展迅速,取得大量可喜结果,也存在许多不足,如细胞分化调节机理,特别是激素诱导的分子机理研究比较薄弱。为建立研究维管组织分化的理想系统,研究嫁接体发育的激素调节机制,在Parkinson和Yeoman发明的离体茎段嫁接系统的基础上,研究了激素对嫁接体发育特别是维管组织分化的影响。 采用不同的嫁接方法,用试管苗对黄瓜离体茎段自体嫁接、亲和性的黄瓜/黑籽南瓜与不亲和性的黄瓜/绿豆离体茎段嫁接组合进行研究,建立了嫁接过程简单、污染率低的试管苗离体茎段嫁接系统。利用往培养基中添加或不加植物激素研究嫁接体发育,发现通过改变培养基中的植物激素,可使亲和的嫁接体难以形成贯通砧木和接穗的维管束桥,也可诱导非亲和性的嫁接体产生维管束桥。初步研究证明利用植物激素可以克服嫁接不亲和性,这一结果是嫁接基础理论研究的一个重要进展,对揭示嫁接亲和性机制具重要意义。由于黄瓜绿豆嫁接组合中,砧木绿豆是可以固氮的豆科植物,研究结果具有潜在的应用前景。 详细地研究了外源IAA和玉米素(ZT)对黄瓜自体嫁接系统中维管束桥形成时间和数目特别是贯通砧木和接穗的管状分子数的影响。当砧木和接穗培养基中都没有添加植物激素时,嫁接接合部难以产生维管束桥,也难以产生贯通的管状分子。当培养基中添加植物激素时,维管束桥数和贯通的管状分子数随激素浓度和种类的不同而不同。本实验的最佳激素条件是:在接穗培养基中加IAA 1.0 mg/L和ZT 0.25 mg/L,在砧木培养基中加ZT 0.25 mg/L。研究表明在试管苗离体茎段自体嫁接系统中,外源激素是嫁接成功的必要条件。试管苗离体茎段嫁接系统是一个理想的研究植物维管组织分化的新系统。 通过对嫁接体发育期接合部及嫁接体各部分IAA、玉米素及玉米素核苷(Z+ZR)的ELISA分析,发现嫁接接合部维管束的再生受IAA和Z+ZR含量的共同调节;连接接穗和砧木维管束桥的分化比维管束的网联要求更高的IAA水平及LAA(Z+ZR)比率。 上述结果为利用嫁接系统研究维管组织分化机理奠定了基础,使进一步研究嫁接体发育的激素调节机理成为可能。

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(第二部分的摘要) 酪蛋白激酶在许多物种的细胞分裂及分化过程中都有重要作用。在水稻中,以经过油菜素内酯处理的水稻幼苗为材料,通过cDNA微矩阵的方法得到了一个全长1939bp的基因OsCKI1(Accession number AJ487966)。该基因编码的蛋白产物属I型酪蛋白激酶(CKIs),含463个氨基酸。RT-PCR及Northern blot结果显示,基因OsCKI1在水稻各组织中表现为组成型表达,并且其表达受油菜素内酯(BR)及脱落酸(ABA)的诱导。在大肠杆菌中对该基因进行原核表达,并用表达后的蛋白粗提物进行酶活测定,显示该蛋白产物可磷酸化CKIs的特异性底物酪蛋白。通过构建OsCKI1的反义载体并转化水稻,对该基因的生理功能进行了研究。对转基因植株的纯系表型进行了观察,显示其根部发育异常,表现为具有较短的初生根、侧根及不定根数目少于对照。进一步研究显示初生根的变短是由于细胞延伸受抑制引起的。以CKI的特异性抑制剂,CKI-7处理野生型植株,也对OsCKI1缺失引起的表型进行了确认。值得注意的是,以外源生长素(IAA)处理转基因及经CKI-7处理过的野生型植株,都能恢复根部表型,使其生长正常。对反义植株初生根及次生根的游离生长素含量测定结果显示,OsCKI1可能在IAA的代谢途径中发挥作用。转基因植株的种子在萌发时对ABA及BR的处理都表现为不敏感,暗示该基因可能在各种激素信号转导途径中都有作用。OsCKI1-GFP双元表达载体的亚细胞定位的研究显示该基因主要定位于核中,可能参与了基因表达的调节。同时,以该反义转基因植株为材料,通过cDNA芯片的技术研究了受OsCKI1调节的基因的表达谱,结果显示该基因的缺失的确影响了参与信号转导及激素代谢途径的许多基因的表达。 (第四部分的摘要) 以OsCKI1反义转基因植株对照植株为材料,研究它们处于4℃低温胁迫下的反应情况。植株种子在室温下萌发并生长一段时间后,移入4℃低温下进一步生长。取对照及低温处理后的材料,对其表型进行观察,显示低温下转基因植株初生根生长受抑制程度小于对照,其生长的延缓程度低;相对电导率测定结果显示,经低温处理后,转基因植株相对电导率变化较小,质膜受害程度小;微管观察结果也显示在短期低温处理下对照根部延伸区细胞的皮层微管解聚,而转基因植株其根部延伸区细胞的皮层微管仍能保持正常状态。基因OsCKI1在低温下的表达模式表现为先升高之后又降低,推测其在低温信号的转导途径中发挥作用。通过总结以上结果,我们认为基因OsCKI1的反义转基因植株虽然在短期冷害下具有一定的抗冷能力,但其不具备形成长期稳定的冷适应的能力。

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We constructed a high redundancy bacterial artificial chromosome library of a seriously endangered Old World Monkey, the Yunnan snub-nosed monkey (Rhinopithecus bieti) from China. This library contains a total of 136 320 BAC clones. The average insert size of BAC clones was estimated to be 148 kb. The percentage of small inserts (50-100 kb) is 2.74%, and only 2.67% non-recombinant clones were observed. Assuming a similar genome size with closely related primate species, the Yunnan snub-nosed monkey BAC library has at least six times the genome coverage. By end sequencing of randomly selected BAC clones, we generated 201 sequence tags for the library. A total of 139 end-sequenced BAC clones were mapped onto the chromosomes of Yunnan snub-nosed monkey by fluorescence in-situ hybridization, demonstrating a high degree of synteny conservation between humans and Yunnan snub-nosed monkeys. Blast search against human genome showed a good correlation between the number of hit clones and the size of the chromosomes, an indication of unbiased chromosomal distribution of the BAC library. This library and the mapped BAC clones will serve as a valuable resource in comparative genomics studies and large-scale genome sequencing of nonhuman primates. The DNA sequence data reported in this paper were deposited in GenBank and assigned the accession number CG891489-CG891703.

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以PCR技术从金黄色葡萄球菌基因组DNA中首次克隆编码成熟SECZ蛋白的全基因sec2。该基因共717bp,编码239个氨基酸,Genbank Accession number:AY450554。构建了SEC2的表达载体pET-28a-sec2,并在大肠杆菌BL21(DE3)中高效表达可溶性rSEC2蛋白。经亲和层析纯化,其纯度在95%以上,平均回收量为每升培养物40mg。纯化的rSEcZ保持了与野生型相当的生物学活性。以限制性核酸内切酶连接技术分别将两个抗人表皮生长因子受体HER-2单链抗体基因通过DNA Linker与sec2融合,构建融合基因b-l-sec2和ml小sec2,并以两种方式表达纯化。以pET-32a表达载体在E,coliAD494(DE3)中以氨基端融合大肠杆菌硫氧还蛋白(TrxA)形式高效表达融合蛋白TRX-B-L-SEC2和TRX-ML-L-SEC2,经亲和层析纯化,并以肠激酶切割得到成熟融合免疫毒素B-L-SEC2和ML-L-SEC2,其纯度在95%以上,平均回收量为每升培养物smg;以构建的新型表达载体pASK-75-EX在E.coliBL21(ED3)中以不溶性包涵体形式表达融合免疫毒素蛋白,经变性、纯化和复性后得到具有生物学活性的融合免疫毒素,其纯度在95%以上,平均回收量为每升培养物30mg。以两种方式制备的融合免疫毒素都保持了SECZ蛋白的免疫原性,都能有效刺激人外周血单个核细胞的增殖,并且都显示出在体外与HER-2过表达的乳腺癌细胞SK-Br-3特异性结合能力,具有显著的靶向性抑瘤作用。用PcR方法扩增了编码TrxA蛋白的基因trxA并克隆至表达载体pET-28a启动子上游,构建了一种在单质粒中利用两个相同的启动子游离共表达硫氧还蛋白与目的蛋白的表达载体。利用该载体可使TrxA与外源蛋白在大肠杆菌BL21(DE3)中以非融合形式高效共表达。共表达的TrxA可明显促进外源蛋白单链抗体ML3.9(scFv-ML)、3一轻基苯甲酸-6-单加氧酶(3HBA)的可溶性表达;并明显减少肠毒素C2(SEC2)、结核杆菌螺旋酶A亚基(GYRA)的包涵体表达。