中国棉铃虫单粒包埋核型多角体病毒多角体蛋白基因的序列分析

以AcMNPV的多角体蛋白基因为探针,定位了中国棉铃虫单粒包理核型多角体病毒（HaSNPV）的多用体蛋白基因。序列测定表明,HaSNPV的多角体蛋白基因编码区为738个核苷酸,编码246个氨基酸,预计蛋白质分子量为29kDa。同源性分析表明,HaSNPV与美洲棉铃虫单粒包理核型多角体病毒（HzSNPV）具有最高的同源性,在整个阅读框架中只有4个碱基的差异,其中第179位碱基的变化导致唯一的氨基酸变化,这种变化并未导致其二级结构的改变。此外,两种病毒该基因的启动子结构也完全一样。HaSNPV与其它的SNPV和MNPV的同源性明显要低。结果预示HaSNPV与HzSNPV可能为同种病毒的不同变种。     

斜纹夜蛾核型多角体病毒BamHI—J片段序列分析

报道了斜纹夜蛾核型多角体病毒（SpltMNPV)BamHI-J片段的序列结构。该片段定位于SpltMNPV基因组25.8-29.9图单位（msp unit）,包括4个完整的开放读码框,几丁质酶基因（chiA）的3′端部分序列和一个同源区（hr）的部分序列。4个完整的读码框包括lef-8基因,杆状病毒J结构域蛋白基因（baculovirus J domain protein gene,bjdp),ORF570和ORF165。序列分离表明：ORF570与毒蛾核型多角体病毒（Lymantria dispar MNPV）的解旋酶－2基因有31％的氨基酸同源性。ORF165为SpltMNPV特有。J结构域蛋白在其他杆状病毒基因组中尚未见报道,其氨基酸序列N端存在J结构域,推断该蛋白质具有与DnaJ蛋白类似特征。lef-8基因编码的氨基酸与已报道的杆状病毒基因组中的lef-8基因编码的氨基酸具有高的同源性,且其C端具有与其他杆状病毒LEF－8类似的保守序列CIKICGIHGQKG。     

粘虫核型多角体病毒多角体蛋白基因结构和序列和研究

测定了粘虫核型我角体病毒两个ＥｃｏＲＶ片段共１２０１ｂｐ序更,发现一个７１４ｂｐ的开放阅读框（ＯＲＦ）,根据其与ＮＰＶ多角体收白基因同源性的比较和５端典型的１４ｂｐ保守序列。说明此ＯＲＦ即为ＬｓＮＰＶ的ｏｃｕ基因。根据核苷邓列预测的多角体蛋白有２４６个氨基酸,其中酸性和碱性氨基酸数相符,疏水氨基酸含理很高,氨基酸组成中以谷氨酸含量最高,谷氨酰胺和半胱氨酸含量最低。编码区碱基同源性与ＭｂＮＰＶ最高,     

日本三株斜纹夜蛾核型多角体病毒的增殖特性及其多角体蛋白基因的序列分析

利用斜纹夜蛾Spodoptera litura培养细胞,对近年来在日本本州、九州和四国等地发现并筛选出的对斜纹夜蛾幼虫具有强烈杀虫活性的3株斜纹夜蛾核型多角体病毒(SpltMNPV)（K-3、G1-2和G10-3）进行了生物学活性和分子生物学的初步研究,克隆了多角体蛋白基因,并进行了序列分析和比较。结果表明:（1）SpltMNPV日本分离株K-3、G1-2和G10-3分别具有不同的特征性酶切图谱,分别属于3种基因型（A型、B型和C型）; （2）3个分离株的芽生型病毒（budded virus）产生能力和多角体产生能力有差异,免疫印迹分析表明,多角体蛋白的分子量也不同;（3）日本株SpltMNPV核型多角体蛋白结构基因由747个核苷酸编码序列（编码249个氨基酸）组成,其序列与中国株SpltMNPV的同源性为98.9%,与其他6种核型多角体病毒有较高的同源性（61.7%～74.2%）,但其5′端侧翼序列(nt-1～-100)与AcMNPV和BmNPV相比差异显著,在对该基因表达调控起决定性作用的8个高度保守核苷酸序列中（nt-44～-51）有2处发生自然突变。     

粘虫核型多角体病毒多角体蛋白基因结构和序列的研究

测定了粘虫核型多角体病毒（Ｌｅｕｃａｎｉａｓｅｐａｒａｔａｎｕｃｌｅａｒｐｏｌｙｈｅｄｒｏｓｉｓｖｉｒｕｓ,ＬｓＮＰＶ）两个ＥｃｏＲＶ片段的共１２０１ｂｐ序列,发现了一个７１４ｂｐ的开放阅读框（ＯＲＦ）,根据其与多种ＮＰＶ多角体蛋白基因（ｏｃｕ）同源性的比较和５＇端典型的１４ｂｐ保守序列,说明此ＯＲＦ即为ＬｓＮＰＶ的ｏｃｕ基因。根据核苷酸序列预测的多角体蛋白有２４６个氨基酸,其中酸性和碱性氨基酸数相等,疏水氨基酸含量很高,氨基酸组成中以谷氨酸（Ｇｌｕ）含量最高,谷氨酰胺和半胱氨酸含量最低。编码区碱基同源性与ＭｂＮＰＶ最高,为９７．０％;氨基酸同源性与ＭｂＮＰＶ最高,为９７．５％。密码子偏爱选用以第三个碱基为嘧啶的密码子。二级结构分析表明,α－螺旋（Ｈ）和β－折叠（Ｓ）相等,β－转角含量是Ｈ和Ｓ含量之和。     

一株雀纹天蛾核型多角体病毒的鉴定及其基因组序列分析

从自然死亡的雀纹天蛾幼虫分离到一株雀纹天蛾核型多角体病毒。通过扫描及切片透射电镜发现,该病毒为单粒包埋型核型多角体病毒,命名为ThjaSNPV(Theretra japonica single nucleopolyhedrovirus)。病毒全基因组重测序后拼接显示,该病毒基因组全长134 899 bp,GC含量37.28%,与豆天蛾单粒包埋型核型多角体病毒株DZ1基因组序列相似性高达96.24%。ThjaSNPV含有131个开放阅读框（ORF）其中55个为正链基因,76个为负链基因,与宿主同为天蛾科的豆天蛾单粒包埋型核型多角体基因组相比,雀纹天蛾单粒包埋型核型多角体病毒新注释到7个基因：chitin-binding protein(ORF9),ODV-E18(ORF11),lef-11(ORF27),hypothetical protein(ORF41),lef-10(ORF42),pif-6(ORF66),P6.9(ORF88)。ThjaSNPV的DNA光裂酶基因（DNA photolyase,ORF53）中不具有豆天蛾NPV中的1bp碱基的缺失,只编码一个大的完整DNA裂合酶。3...     

马尾松毛虫质型多角体病毒多角体蛋白基因的cDNA克隆及序列分析

通过对马尾松毛虫质型多角体病毒的增殖、纯化,获得一株单一类型的质型多角体病毒。提纯的病毒粒子经SDS－酚抽提,琼脂糖凝胶电泳分离基因组dsRNDA,回收纯化第十片段S10。S10经DMSO变性,逆转录合成cDNA第一链,PCR扩增后,克隆在pGEM-T载体上,对重组子进行限制性内切酶分析及序列测定。结果表明,克隆片段全长763bp,起始密码AUG位于3－5残基,终止密码UGA位于747－749残基。推测DpCPV多角体蛋白基因编码248个氨基酸的多肽,分子量28kD。和家蚕质型多角体病毒（BmCPV）多角体蛋白基因相比较,核苷酸和编码氨基酸序列同源性分别为89.3%和97.6%。     

苜蓿丫纹夜蛾核型多角体病毒(AcMNPV)大立方形多角体突变株的分子生物学研究

利用空斑技术,从既能形成多角体又含ＴＫ酶基因的苜蓿丫纹夜蛾重组核型多角体病毒ＡｃＭＮＰＶ－ＴＫ中,纯化了一株形成大立方形多角体的病毒突变株ＡｃＭＮＰＶ－ＴＫｍｔ５１３。用ＥｃｏＲＩ、ＰｓｔⅠ、ＢｇｌⅡ及ＫｐｎⅠ等限制性内切酶对它做了酶切分析,并克隆了多角体蛋白全基因及其侧翼部分的片段。对所克隆的部分全序列测定结果,发现在多角体蛋白基因读码框内只出现了一个碱基的突变,导致了第２５位的氨基酸密码子由ＧＧＴ变为ＧＡＴ,该位氨基酸由甘氨酸（Ｇｌｙ）变为天冬氨酸（Ａｓｐｑ）还利用ＰＣＲ技术扩增出突变了的多角体蛋白基因部分片段,并将它克隆入转移载体质粒ｐＥＶ５５,与不形成多角体的重组病毒ＴｎＮＰＶ－ＨＢｓＤ４ＤＮＡ共转染Ｓｆ９细胞,结果产生同样的大立方形多角体病毒。     

家蚕核型多角体病毒基因polh的诱变分析

曾报道经化学诱变剂ＭＭＣ、９－ＡＡ和ＥＭＳ诱变的家蚕核型多角体病毒（ＢｍＮＰＶ）多角体形态出现异常,继代分离的诱变ＢｍＮＰＶ基因组对ＥｃｏＲＩ、ＢｇｌＩＩ和ＢａｍＨＩ的酶切谱发生变化。研究进一步揭示,诱变ＢｍＮＰＶ的多角体外层蛋白晶格排列呈现紊乱;多角体蛋白的ＳＤＳ－ＰＡＧＥ电泳谱与对照组比较有显著差异;对多角体蛋白基因ｐｏｌｈ的测序结果显示,３组诱变ＢｍＮＰＶ的ｐｏｌｈ基因发生了多处碱基（氨基酸     

马尾松毛虫质型多角体病毒多角体蛋白基因的cDNA克隆及序列分析

通过对马尾松毛虫质型多角体病毒的增殖、纯化,获得一株单一类型的质型多角体病毒.提纯的病毒粒子经SDS-酚抽提,琼脂糖凝胶电泳分离基因组dsRNDA,回收纯化第十片段S10.S10经DMSO变性,逆转录合成cDNA第一链,PCR扩增后,克隆在pGEM-T载体上.对重组子进行限制性内切酶分析及序列测定,结果表明,克隆片段全长763bp,起始密码AUG位于3～5残基,终止密码UGA位于747～749残基.推测DpGPV多角体蛋白基因编码248个氨基酸的多肽,分子量28kD.和家蚕质型多角体病毒(BmCPV)多角体蛋白基因相比较,核苷酸和编码氨基酸序列同源性分别为89.3%和97.6%.     

THE CLONING, SEQUENCING AND EXPRESSION OF THE LdMNPV POLYHEDRIN GENE

Abstract  LdMNPV - NEFU isolate collected from the forestry farm of Northeast Forestry University was purified and the genomic DNA of MMNPV was extracted. The LdMNPV polyhedrin gene was cloned by PCR. The results showed that the sequence was an open reading frame (ORF) of 735bp capable of encoding 245 amino acids. The polyhedrin gene sequences of the MMNPV-NEFU isolate and a Canada strain, MMNPV-G differed in 5 bases. The polyhedrin gene of the LdMNPV-NEFU isolate contained C, G, T, C and G at 54, 109,379, 508 and 701 sites from the start codon, but the LdMNPV-G isolate contained G, C, C, T and T at the corresponding sites respectively. The same amino acids were encoded by the two ORF sequences, with the exception that Asp and His are encoded by GAC on the polyhedrin gene sequence of the LdMNPV-NEFU isolate and by CAC in the MMNPV-G isolate. The MMNPV polyhedrin gene was expressed in E. coli BL21 (DE3) by the pT7–7 plasmid vector.     

繁缕核糖体失活蛋白基因克隆及序列分析

采用同源克隆结合RACE法,克隆了繁缕核糖体失活蛋白的全长cDNA,命名为q3(GenBank accession GQ870262)。序列分析结果表明,q3的开放阅读框(ORF)长780 bp,编码259个氨基酸。序列G+C含量为41.5%,与大部分Ⅰ型RIP基因相近。q3编码的蛋白质命名为Q3,理论分子量为28.16 kD,pI为9.44,均与Ⅰ型核糖体失活蛋白相近;包含由23个氨基酸组成的信号肽。功能结构域分析发现,该蛋白含有3个蛋白激酶磷酸化位点、4个络氨酸蛋白激酶磷酸化位点和7个N-肉豆蔻酰化位点。三级结构预测发现,有35.52%的氨基酸残基参与了α螺旋,24.32%的氨基酸残基组成延伸链,40.15%的氨基酸残基随机缠绕其中。基于繁缕及其近缘种核糖体失活蛋白的氨基酸序列构建的系统发育树显示,其结构与经典分类结果基本一致。     

甜菜坏死黄脉病毒内蒙分离物自然缺失突变体缺失区域的定位分析

以甜菜坏死黄脉病毒内蒙分离物（ＢＮＹＶＶ ＮＭ）总ＲＮＡ为模板,经ＲＴ－ＰＣＲ扩增,分别获得ＲＮＡ２、ＲＮＡ３和ＲＮＡ４自然缺失突变体ｃＤＮＡ克隆。序列分析结果表明,ＲＮＡ２自然缺失突变体在７５ｋＤ通读蛋白编码区Ｃ端缺失３４８个核苷酸（缺失位置ｎｔ１４８８￣ｎｔ１８３５）。ＲＮＡ３在其２５ｋＤ蛋白编码区内缺失３６０个核苷酸（缺失位置ｎｔ７２９￣ｎｔ１０８８）。ＲＮＡ４的自然缺失区域位于３１ｋＤ蛋白     

鹅副粘病毒WF（01）G株F基因的测序与蛋白特性分析

用鹅副粘病毒WF01G分离株进行9-10日龄SPF鸡胚尿囊腔接种,成功增殖了该病毒,采用一步法RT-PCR技术扩增WF01G病毒的F基因,获得了1条长约1.7 kb的特异性条带。对PCR扩增产物测序。结果表明,扩增片段大小为1782 bp,含有1个1662 bp的开放性阅读框,编码554个氨基酸。核苷酸同源性分析表明：WF01G株与其他7株鹅副粘病毒的同源性为84.8%-98.8%,与国内外其他NDV F基因的同源性为84.7%-93.8%,其中与国内标准强毒株F48E9的同源性为86.8%,说明WF01G与国内外的传统毒株有较大变异。与Tai-wan95株的同源性为93.8%,说明WF01G与Taiwan95株亲缘关系较近,具有较高的相似性。F蛋白裂解位点的氨基酸顺序为112Arg-Arg-G ln-Lys-Arg-Phe117,表明为副粘病毒强毒株。蛋白疏水性和抗原性分析表明与标准强毒F48E9株相比没有太大的变异。     

Characterization of the full length uracil-DNA glycosylase in the extreme thermophile Thermotoga maritima

A full length (192 amino acids) uracil-DNA glycosylase (TMUDG) has been expressed and purified from the extreme thermophile Thermotoga maritima. This protein is active up to 85 degrees C. The enzyme is product inhibited by abasic sites in DNA and weakly inhibited by uracil. TMUDG was originally cloned from an ORF which encoded a protein of 185 amino acids. This shorter protein was stable up to 70-75 degrees C and it seemed unusual that this enzyme had an optimal activity temperature below the growth temperature of the organism (80-90 degrees C). Following the publication of the complete genomic sequence of T. maritima, it was shown that the gene contains an additional seven amino acids (LYTREEL) at the N-terminal end of the protein. It is suggested that these seven residues are important in maintaining proper protein folding that results in increased temperature stability. We have also demonstrated that TMUDG can substitute for the Escherichia coli uracil-DNA glycosylase and initiate base excision repair using a closed circular DNA substrate containing a unique U:G base pair.     

Nucleotide sequence of Lymantria dispar nuclear polyhedrosis virus polyhedrin gene

The polyhedrin gene of the nuclear polyhedrosis virus of the gypsy moth (Lymantria dispar) (LdMNPV) was cloned and sequenced. A polyhedrin open reading frame of 735 nucleotides (nt) was identified which can code for a protein of 245 amino acids that demonstrates a high degree of similarity to other polyhedrins. The protein predicted from the nucleotide sequence shows differences in several regions to that previously sequenced from the LdMNPV polyhedrin protein. The consensus sequence AATAAGTATTTT found at the mRNA start site of baculovirus hyperexpressed genes was located 55 nt upstream from the translational start site.     

Primary amino acid and DNA sequences of gassericin T, a lactacin F-family bacteriocin produced by Lactobacillus gasseri SBT2055

A broad-spectral bacteriocin, named gassericin T, produced by Lactobacillus gasseri SBT 2055 (from human feces) was isolated to homogeneity from the culture supernatant by hydrophobic chromatography. By SDS-PAGE and in situ activity assay, the purified gassericin T migrated as a single band with bacteriocin activity and molecular size of 5,400. A 2.9-kbp HindIII-HindIII fragment of chromosome DNA was hybridized with the oligonucleotide probe designed from the partial N-terminal amino acid sequence of gassericin T and was cloned. Six ORFs including the structural gene of gassericin T were deduced by computer analysis and the data bases. The structural gene of gassericin T (gatA) was identified as the fourth ORF, which encoded a protein composed of 75 amino acids that included the GG motif of the cleavage site. Chemical sequencing analysis of the complete amino acid sequence showed that gassericin T (57 amino acids) had a disulfide bond in the molecule and no modified amino acid residues, making it a class II bacteriocin. The gassericin T had 60% sequence similarity to mature LafA (57 amino acids, lactacin F, bacteriocins produced by L. johnsonii VPI11088), and the sequences around the processing site and C-terminal area were well conserved. The fifth ORF was designated as gatX, encoded as a peptide composed of 65 amino acids containing the GG motif of the putative cleavage site, however mature GatX and its antibacterial activity were not detected in the culture supernatant. GatX has higher similarity with LafX than with lactobin A (50 amino acids) belonging to the first lactacin F-family. These results indicated that gassericin T belongs to the hydrophobic class II bacteriocins and the most vicinal lactacin F-family.     

黄河裸裂尻鱼细胞色素C氧化酶Ⅰ、Ⅱ和Ⅲ亚基基因的克隆及序列特征分析

采用RT-PCR技术克隆获得了黄河裸裂尻鱼(Schizopygopsis pylzovi)CO Ⅰ、Ⅱ、Ⅲ基因的编码序列,并对此进行了初步分析.结果表明,黄河裸裂尻鱼CO I基因全长为1 551 bp,开放阅读框(ORF)由基因全长组成,编码516个氨基酸;COⅡ基因全长为691 bp,开放阅读框为690 bp,编码2...