共查询到20条相似文献,搜索用时 18 毫秒
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苏云金芽胞杆菌大质粒pBMB165的克隆与分析 总被引:1,自引:0,他引:1
以pBeloBAC11为载体,成功构建了苏云金芽胞杆菌YBT-1765的基因组人工染色体(BAC)文库和质粒BAC文库.根据已克隆的包含复制子ori165在内的3.6kb片段中编码复制蛋白Rep165的核苷酸序列设计探针,通过染色体步移方式,对质粒文库和基因组文库进行筛选,得到13个覆盖YBT-1765菌株中质粒pBMB165不同区域的克隆子.通过Hind Ⅲ和BamH Ⅰ酶切分析,建立了质粒pBMB165的物理图谱和线状重叠连锁图,并测算出该质粒的大小为82kb.根据部分核苷酸序列初步统计了pBMB165上转座因子的存在机率.YBT-1765菌株基因组文库的构建和物理图谱的绘制为克隆苏云金芽胞杆菌大质粒提供了一套可行的方案,成功解决了大质粒难克隆的问题. 相似文献
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分子克隆是现代生物学研究的核心技术之一,是基因工程、蛋白质工程中的重要手段。为提高分子克隆实验的操作效率,本研究设计并合成基于聚合酶引物不完全延伸(polymerase incomplete primer extension,PIPE)现象的质粒克隆位点序列。并以此为基础统一相关引物的设计方案,避免传统酶切--连接法中需针对不同载体MCS序列设计不同引物的缺点。该方案利用13 bp定长接头序列,在同一体系中使用2对引物、2种线性化模板同时扩增载体和插入片段,通过20个循环,在1次PCR过程中即合成可供转化使用的带缺口质粒产物。在NEB Q5酶系统中,利用此法将3种荧光素酶序列插入pET-15b及pET-21b(+)载体,均获得成功。且利用商品化感受态细胞(转化效率 > 5×108 cfu/μg)转化后所获得转化子数量均在300个以上,其中含插入片段的阳性克隆比例可达85%以上。基于本方案的设计及作用原理,可将其应用于10 kb以内载体和插入片段的快速重组。且具有通用性强、耗时少、阳性克隆得率高和成本低等优点,是传统DNA重组方法的有益补充,可作为各实验室的常规分子克隆手段之一。 相似文献
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Ekaterina A. Bogdanova Irina A. Shagina Elena Mudrik Igor Ivanov Peter Amon Laura L. Vagner Sergey A. Lukyanov Dmitry A. Shagin 《Molecular biotechnology》2009,41(3):247-253
A novel DSN-depletion method allows elimination of selected sequences from full-length-enriched cDNA libraries. Depleted cDNA
can be applied for subsequent EST sequencing, expression cloning, and functional screening approaches. The method employs
specific features of the kamchatka crab duplex-specific nuclease (DSN). This thermostable enzyme is specific for double-stranded
(ds) DNA, and is thus used for selective degradation of ds DNA in complex nucleic acids. DSN depletion is performed prior
to library cloning, and includes the following steps: target cDNA is mixed with excess driver DNA (representing fragments
of the genes to be eliminated), denatured, and allowed to hybridize. During hybridization, driver molecules form hybrids with
the target sequences, leading to their removal from the ss DNA fraction. Next, the ds DNA fraction is hydrolyzed by DSN, and
the ss fraction is amplified using long-distance PCR. DSN depletion has been tested in model experiments.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
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Sijing Jiang Xing Zhong Chao Zhai Liang Chen Lixin Ma Meilin Jin Huanchun Chen 《Biotechnology letters》2010,32(7):903-907
The large capacity of pseudorabies virus (PRV) for foreign DNA and broad host range make it a prospective tool for the preparation of vaccines and agents of gene and tumour therapy. Here we introduced a cloning strategy that facilitates construction of recombinant PRV?CBAC vectors based on mating-assisted genetically integrated clone (MAGIC). The target gene was cloned into a small conditionally replicating donor plasmid, followed by shuffling to a recipient PRV?CBAC plasmid in vivo of Escherichia coli through MAGIC. The average efficiency of successful clones was 89%. Moreover, permanent integration of unwanted sequences was avoided. 相似文献
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一种来源于链霉菌的纤溶酶的纯化及其基因的克隆 总被引:1,自引:0,他引:1
链霉菌C3662的发酵液上清经 80 %硫酸铵沉淀 ,DEAE Sepharose和CM Sepharose层析分离后纯化出一种纤溶酶。SDS PAGE显示为单一的条带 ,分子量约为 30kD。以 pIJ699为载体 ,S .lividansTK2 4为宿主菌 ,鸟枪法克隆纤溶酶基因 ,从 30 0 0个转化子中挑选到 1个具活性转化子 ,经亚克隆 ,序列测定得到一个 90 3bp的完整ORF ,其GC %为 68.33% ,密码子第三位GC %为 95.6% ,符合链霉菌基因的典型特征。与多种蛋白酶具有较高的同源性 相似文献
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《Gene》1997,185(2):195-199
Gene cloning is a time-consuming task for molecular biologists, because it often takes weeks or months to construct, screen and finally clone a gene from a DNA library. Thus, more effective methods are needed for gene cloning. This paper describes a modified polymerase chain reaction (PCR) cycling condition, Uneven PCR, to generate specific unknown fragments or genes directly from total DNA instead of cloning fragments from DNA libraries. The essence of the method is to use two different annealing temperatures in consecutive PCR cycles to effectively amplify the target products while inhibiting the synthesis of non-specific products. Under favorable conditions, a desired DNA fragment or gene in the size range up to approximately 4 kb can be obtained and ready for cloning within a day or two. 相似文献
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Siddamadappa Chandrashekaran Padmanabhan Babu Valakunja Nagaraja 《Journal of biosciences》1999,24(3):269-277
The genes encoding theKpnI restriction endonuclease and methyltransferase fromKlebsiella pneumoniae have been cloned and expressed inEscherchia coli using a two plasmid strategy. The gene forKpnI methylase with its promoter was cloned and expressed in pACYC184. Even though the methylase clone is in a low copy number
plasmid pACMK, high level expression of methylase is achieved. A hyper-expressing clone ofKpnI endonuclease, pETRK was engineered by cloning the R gene into the T7 expression system. This strategy resulted in over-expression
ofKpnI endonuclease to about 15–30% of cellular protein. Both the enzymes were purified using a single Chromatographic step to
apparent homogeneity. The yield of purified endonuclease and methylase from one liter of culture was approximately 30 and
6 mg respectively. Electrophoretic mobility shift assays show that both the enzymes are capable of binding to specific recognition
sequence in the absence of any cofactors. The complexes ofKpnI methyl transferase and endonuclease with their cognate site exhibit distinctive behaviour with respect to ionic requirement. 相似文献
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Novel one-step cloning vector with a transposable element: application to the Myxococcus xanthus genome. 总被引:11,自引:8,他引:3 下载免费PDF全文
A new strategy was developed for rapid cloning of genes with a transposon mutation library. We constructed a transposon designated TnV that was derived from Tn5 and consists of the gene coding for neomycin phosphotransferase II as well as the replication origin of an Escherichia coli plasmid, pSC101, flanked by Tn5 inverted repeats (IS50L and IS50R). TnV can transpose to many different sites of DNA in E. coli and Myxococcus xanthus and confers kanamycin resistance (Kmr) to the cells. From the Kmr cells, one-step cloning of a gene which is mutated as a result of TnV insertion can be achieved as follows. Chromosomal DNA isolated from TnV-mutagenized cells is digested with an appropriate restriction enzyme, ligated, and transformed into E. coli cells with selection for Kmr. The plasmids isolated contain TnV in the target gene. The plasmid DNA can then be used as a probe for characterization of the gene and screening of clones from a genomic library. We used this vector to clone DNA fragments containing genes involved in the development of M. xanthus. 相似文献
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Rapid extraction and purification of environmental DNA for molecular cloning applications and molecular diversity studies 总被引:2,自引:0,他引:2
Santosa DA 《Molecular biotechnology》2001,17(1):59-64
A rapid method for the extraction and purification of DNA from environmental samples for molecular cloning applications was
developed. The indigenous cells from plant debris, organic materials, sediments, and soils were lysed directly by using DAS-IZ solution and the nucleic acids were precipitated with isopropanol. A simple purification step using DAS-IIZ solution without binding matrix produced highly pure, colorless and undegraded DNA with molecular weight of more than 20
kb. The superiority of this method was tested for wide applications in molecular cloning, i.e., construction of genomic library
by using Lambda DASH(R)II Vector and Gigapack(R)III XL, plasmid library, cloning of gene encoding protease, and molecular microbial diversity analysis. An additional advantage
of this method is that only 0.1 g of sample is required, if analysis of many samples in short time should be done. To extract
large amounts of environmental DNA for molecular cloning lasts only 30 min and to purify it less than 1 h. 相似文献
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Vishnu Vardhan Krishnamurthy John S. KhamoEllen Cho Cara SchornakKai Zhang 《Analytical biochemistry》2015
Precise DNA manipulation is critical for molecular biotechnology. Restriction enzyme-based approaches are limited by their requirement of specific enzyme sites. Restriction-free cloning has greatly improved the flexibility and speed of precise DNA assembly. Most of these approaches focus on DNA assembly rather than gene removal. Here we present a polymerase chain reaction (PCR)-based cloning method that allows removal of multiple gene segments from plasmids without using restriction enzymes and thermostable ligase. We demonstrate simultaneous removal of three gene segments from a plasmid. This approach could be beneficial to DNA library construction, genetic and protein engineering, and synthetic biology. 相似文献
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本文报道了以质粒pUB110为载体,以枯草芽孢杆菌(Bacillus subtilis 168)作为受体菌,对丁酰苷菌素产生菌(Bacillus circulans NRRL-B3312)总DNA进行了鸟枪克隆,在所获得的转化子中,No.733转化子经薄层层析,生物显迹和质谱分析表明,它具有将卡那霉素A生物转化成为丁胺卡那霉素的能力,说明该转化子所含重组质粒pUBC733的插入片段中含有a-羟基-r-氨丁酰(HABA)酰化酶基因,HABA酰化酶基因已经在枯草芽孢杆菌中获得了克隆和表达。该重组质粒分子量为7.3kb,插入片段为2.8kb,经Southern分子杂交确证此片段确来源于环状芽孢杆菌,已构建了该质粒限制性内切酶图谱。 相似文献
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新生隐球菌STE12α基因的克隆及表达载体的构建 总被引:1,自引:0,他引:1
目的从新生隐球菌的基因组中扩增出STE12α基因,并构建相应的表达载体,以进一步研究STE12α基因对隐球菌的生长特性及致病性的影响。方法采用PCR方法以及基因重组方法扩增并克隆新生隐球菌基因组中的STE12α基因,建立具有表达野生型STE12α基因的表达载体。结果从新生隐球菌的基因组获得STE12α全基因,建立重组子pUCm—STE12α/NovaBlue以及重组表达载体质粒pGAPZ—STE12α,实现了STE12α基因的转化并获得表达。结论成功地克隆了新生隐球菌STE12α基因并构建了可表达野生型STE12α基因的表达载体,为进一步研究STE12α基因功能打下了良好的基础。 相似文献
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We have constructed a plasmid useful for insertional mutagenesis inStreptococcus mutans.The molecule, pSU20Erm, is based on a derivative of pACYC184 known as pSU20. The plasmid described here is approximately 3.7 kb in size and has the following properties: it replicates inEscherichia coli,does not replicate inS. mutans,contains an erythromycin-resistance marker which can be selected inE. colior the streptococci, contains a multiple cloning site with few restriction sites in the remainder of the molecule, and can be screened on X-Gal-containing medium for the presence of insertions into the multiple cloning site. We have used the plasmid to construct a library ofS. mutansDNA inE. coliand show that the clones can be reintegrated into theS. mutanschromosome via homologous recombination, thereby interrupting native genes. The plasmid has been used to clone part of a homologue of theE. coli drpAgene, encoding a global regulatory element for RNA synthesis. Further, we have identified an element closely linked todrpAinS. mutanswith high homology to IS861. 相似文献
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旋毛虫肌幼虫ES抗原的基因克隆及高效表达 总被引:7,自引:0,他引:7
作者对编码旋毛虫肌幼虫ES抗原的部分结构基因进行了克隆、鉴定和表达。用RNA PCR技术直接从旋毛虫肌幼虫总RNA中反转录并扩增出0.7kh的靶DNA,酶切分析后将其克隆到融合表达载体pEx3lC中。SDS—PAGE电泳表明,含重组子的大肠杆菌能够表达出一分子量为37kDa的融合蛋白(P37),后者占菌体总蛋白的22%以上,并以包含体形式存在于菌体中。经对纯化后表达蛋白的ELlSA检测,证明它能被猪旋毛虫病阳性血清和抗旋毛虫单克隆抗体识别。研究结果揭示,重组蛋白P37对于研制旋毛虫病诊断抗原和免疫抗原具有潜在的应用价值。 相似文献
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目的 从巨噬细胞系RAW264.7基因组中扩增甘露糖受体(MR)基因,克隆至穿梭质粒后包装重组腺病毒,以进一步研究甘露糖受体MR基因对树突状细胞参与抗新生隐球菌免疫的影响.方法 采用PCR方法以及基因重组方法扩增并克隆巨噬细胞基因组中的MR基因,包装能表达MR蛋白的重组腺病毒.结果 从巨噬细胞基因组获得MR全基因,克隆至pShuttle-CMV载体,包装了MR的重组腺病毒AD-MR,并在HEK293细胞中获得了表达.结论 成功克隆巨噬细胞MR基因并构建了可表达MR基因的重组腺病毒载体,为进一步研究MR基因在树突状细胞参与新生隐球菌免疫中的作用奠定基础. 相似文献
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A fragment of the α-fetoprotein (AFP) structural gene was purified and amplified by bacterial cloning techniques. Double-stranded DNAAFP was constructed from a cDNA copy of greater than 95% pure mRNAAFP and inserted into E. coli plasmid pBR322 by poly(dA-dT)-linkers. Chimeric plasmid DNA isolated from transformants of E. coli strain χ1776 have been shown to contain α-fetoprotein sequences by hybridization to labeled mRNAAFP. One clone, designated pA5 (chimeric plasmid pBR322 containing a cDNAAFP sequence isolated from clone 5), has been studied in more detail. The inserted sequence of approximately 950 nucleotide pairs was positively identified by a hybridization-translation procedure. Hybridization of [3H]uridine-labeled poly(A)-containing RNA from an AFP-secreting cell line to excess pA5 DNA immobilized on nitrocellulose filters was used to show the selectivity of this probe for detecting expression of the AFP gene. 相似文献