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1.
The complete nucleotide sequence of the genome of the Sabin vaccine strain of poliovirus type 3 (P3/Leon 12 a1 b) has been determined from cDNA cloned in E. coli. The genome comprises a 5' non-coding region of 742 nucleotides, a large open reading frame of 6618 nucleotides (89% of the sequence) and a 3' non-coding region of 72 nucleotides. There is 77.4% base-sequence homology and 89.6% predicted amino-acid homology between types 1 and 3. Conservation of all glutamine-glycine and tyrosine-glycine cleavage sites suggests a mechanism of polyprotein processing similar to that established for poliovirus type 1.  相似文献   

2.
A viable insertion mutant of the Sabin strain of type 1 poliovirus was constructed. The mutant carried an insertion sequence of 72 nucleotides at nucleotide position 702 in the 5' non-coding region (742 nucleotides long) of the genome of the Sabin strain. This mutant showed a small-plaque phenotype, as compared with the parental virus. Indeed, the final yield of the mutant in a single cycle of infection was tenfold fewer than that of the parental virus. Many large-plaque variants that are easily generated from the insertion mutant appeared to regain efficient viral replication and have single nucleotide changes. All nucleotide changes observed were limited to within three nucleotides of an AUG sequence in the insertion sequence. The result indicates strongly that the AUG sequence itself in this genome region functions in reducing the plaque size of the parental Sabin type 1 virus. The insertion mutant with a small-plaque phenotype may be the first in vitro mutant of poliovirus whose viability is lowered only by a primary sequence inserted into the 5' non-coding region of the genome. Base substitutions to alter the AUG sequence should largely be the result of errors of the virus-specific replicase, since variants with base substitutions must be subject to only minimum selection pressure. Accordingly, nucleotide sequence analysis of the genome region containing the AUG sequence was performed on a number of genomes of large-plaque variants to investigate types of nucleotide substitutions caused by characteristic errors in RNA replication. Only one transversion mutation was detected in the genomes of 44 independently isolated large-plaque variants with single base changes in the AUG sequence. This result suggests strongly that transition mutations occur predominantly as nucleotide substitutions caused by characteristic errors of poliovirus replicase.  相似文献   

3.
cDNA clones representing the entire genome of human rhinovirus 2 have been obtained and used to determine the complete nucleotide sequence. The genome consists of 7102 nucleotides and possesses a long open reading frame of 6450 nucleotides; this reading frame is initiated 611 nucleotides from the 5' end and stops 42 nucleotides from the polyA tract. The N-terminal sequences of three of the viral capsid proteins have been elucidated, thus defining the positions of three cleavage sites on the polyprotein. The extensive amino acid sequence homology with poliovirus and human rhinovirus 14 enabled the other cleavage sites to be predicted. Cleavages in the 3' half of the molecule appear to take place predominantly at Gln-Gly pairs, whereas those in the 5' half (including the capsid proteins) are more heterogeneous.  相似文献   

4.
We report the sequence of a 1164 nucleotide long DNA segment, located between map positions 59.5 and 62.8 on the adenovirus type 2 genome. The sequence comprises the 701 nucleotides long 3' non-coding region of the hexon mRNA as well as several important processing signals. The sequence revealed unexpectedly that the 3' non-coding region of the hexon mRNA contains a 609 nucleotide long uninterrupted translational reading frame following a potential initiator AUG. A late 14S mRNA, corresponding to the open reading frame, could be identified by S1 nuclease mapping and electronmicroscopy. The mRNA shares a poly(A) addition site with the hexon and pVI mRNAs, and carries a leader sequence which is related, and probably identical, to the tripartite leader, found in late adenovirus mRNAs. The junction between the leader and the body of this novel mRNA is located within the coding part of the hexon gene.  相似文献   

5.
The nucleotide sequence of two zein cDNAs in hybrid plasmids A20 and B49 have been determined. The insert in A20 is 921 bp long including a 5' non-coding region of 60 nucleotides, preceded by what is believed to be an artifactual sequence of 41 nucleotides, and a 3' non-coding region of 87 nucleotides. The B49 insert is 467 bp long and includes approximately one-half the protein coding sequence as well as a 3' non-coding region of 97 nucleotides. These sequences have been compared with the previously published sequence of another zein clone, A30 . A20 and A30 , both encoding 19 000 mol. wt. zeins , have approximately 85% homology at the nucleotide level. The B49 sequence, corresponding to a 22 000 mol. wt. zein, has approximately 65% homology to either A20 or A30 . All three zeins share common features including nearly identical amino acid compositions. In addition, the tandem repeats of 20 amino acids first seen in A30 are also present in A20 and B49 .  相似文献   

6.
The nucleotide sequence for an unusual, cloned human adenosine deaminase cDNA has been determined. Contained within a sequence of 1535 nucleotides is a coding sequence of 1089 nucleotides that encodes a protein of 40,762 daltons. The coding sequence is interrupted by a non-coding region containing 76 nucleotides. Both the 3' and 5' ends of this region have consensus sequences generally associated with splice sites. The 3' untranslated sequence contained 308 nucleotides, including a polyadenylation signal sequence 20 nucleotides from the end. The cloned cDNA appears to correspond to a nuclear mRNA precursor which contains a small intron.  相似文献   

7.
N Takamatsu  T Ohno  T Meshi    Y Okada 《Nucleic acids research》1983,11(11):3767-3778
The cDNA copies of tobacco mosaic virus (TMV)-tomato strain (L) genome were cloned by the method of Okayama and Berg (Mol. Cell. Biol. 2, 161-170. (1982)) and the sequence of 1,614 nucleotides at the 3' end was determined. The sequence encompasses the 30K and the coat protein cistron which are located in residues 685-1, 479 and 203-682 from the 3' end of the genome respectively. The close relationship between the tomato and the common strain was shown on the level of the nucleotide sequence. Highly homologous regions are found in the 3' non-coding region, the assembly origin and the 5' flanking region of the 30K protein cistron. The comparison of the deduced amino acid sequence between the tomato and the common strain shows that the 30K protein is composed of the conserved N-terminal four-fifth and the highly divergent region near the C-terminus.  相似文献   

8.
The nucleotide sequence of the gene which encodes the major outer-shell glycoprotein of UK bovine rotavirus has been determined. The dsRNA genome segment encoding this protein was converted into ds cDNA and cloned into pBR322 for sequence studies. The gene is 1062 base pairs in length and contains a single, long, open reading-frame capable of coding for a protein of 326 amino-acids. This would leave 5' and 3' non-coding regions of 48 and 36 nucleotides in the mRNA. The predicted amino-acid sequence contains three possible glycosylation sites of the type Asn-X-Ser Thr, and an extremely hydrophobic N-terminal region. This sequence is discussed in the light of the known properties and functions of the protein.  相似文献   

9.
A cDNA for alpha-globin mRNA of the carp, Cyprinus carpio, was cloned by the method of Okayama and Berg (Mol. Cell. Biol. 2 (1982) 161-170) and its complete nucleotide sequence was determined. The 5' non-coding region contained 23 nucleotides. Following this region, there was an open reading frame encoded with an alpha-globin polypeptide consisting of 142 amino acids. The 3' non-coding region was 88 nucleotides in length, including two copies of the hexanucleotide AATAAA and a poly(A) site of the GC dinucleotide. There were 16 discrepancies between the reported amino acid sequence of the carp alpha-globin chain and the amino acid sequence predicted from the DNA sequence of the clone. The possible explanations for these differences in amino acid sequence are discussed.  相似文献   

10.
S Ozden  F Tangy  M Chamorro    M Brahic 《Journal of virology》1986,60(3):1163-1165
Theiler's virus causes a persistent demyelinating infection of the mouse central nervous system. Our study of the molecular mechanism of persistence led us to sequence 1925 nucleotides located at the 3' end of the viral genome. We observed extensive homologies between this region and the corresponding region of encephalomyocarditis virus, the prototype cardiovirus, and only some homologies with the 3' ends of foot-and-mouth disease virus, rhinovirus, and poliovirus genomes.  相似文献   

11.
Based on reported TMV-U1 sequence, primers were designed and fragments covering the entire genome of TMV broad bean strain (TMV-B) were obtained with RT-PCR. These fragments were cloned and sequenced and the 5' and 3' end sequences of genome were confirmed with RACE. The complete sequence of TMV-B comprises 6 395 nucleotides (nt) and four open reading frames, which correspond to 126 ku (1 116 amino acids), 183 ku (1 616 amino acids), 30 ku (268 amino acids) and 17.5 ku proteins (159 amino acids). The complete nucleotide sequence of TMV-B is 99.4% identical to that of TMV-U1. The two virus isolates share the same sequence of 5', 3' non-coding region and 17.5 K ORF, and 6, 1 and 3 amino acid changes are found in 126 K protein, 54 K protein and 30 K protein, respectively. The possible mechanism on the infection of TMV-B in Vicia faba is discussed.  相似文献   

12.
13.
赵新泰  李载平 《遗传学报》1993,20(3):279-284
本试验测定了已克隆的貂肠炎病毒(MEV)复制型(RF)DNA的核苷酸序列,确定MEV基因组全长约为5064个核苷酸(nucleotides,nt),推测了3'端和5'端结构,在5'端非编码区有3个51 nt的重复。MEV基因组序列与犬细小病毒(CPV)、猫细小病毒(FPV)有很高的同源性,结构基因区的同源性分别达99.1%和99.9%,但在5'端非编码区有较大差异。MEV基因组结构与CPV和FPV基本一致,有两个大的开放阅读框架,分别编码688和722个氨基酸。在map unit(m.u.)3.7和m.u.39处有两个启动子,在m.u.97处有poly A位点。NS2、VP1和VP2的mRNA都发生剪接。  相似文献   

14.
The complete nucleotide sequence of the coding region of foot and mouth disease virus RNA (strain A1061) is presented. The sequence extends from the primary initiation site, approximately 1200 nucleotide from the 5' end of the genome, in an open translational reading frame of 6,999 nucleotides to a termination codon 93 nucleotides from the 3' terminal poly (A). Available amino acid sequence data correlates with that predicted from the nucleotide sequence. The amino acid sequence around cleavage sites in the polyprotein shows no consistency, although a number of the virus-coded protease cleavage sites are between glutamate and glycine residues.  相似文献   

15.
Complete nucleotide sequence of ovine alpha-lactalbumin mRNA   总被引:1,自引:0,他引:1  
The nucleotide sequence of ovine alpha-lactalbumin mRNA has been determined by chemical sequencing of two cDNA recombinant plasmids and a primer extension product. Ovine alpha-lactalbumin mRNA contains 723 nucleotides (excluding the poly(A) tail), with a 5' non-coding region of 26 nucleotides, followed by the 426 nucleotides of the coding region which determines a sequence signal of 19 amino acid residues and the 123 amino acid residues of mature alpha-lactalbumin. The coding region is followed by a 3' untranslated sequence of 271 nucleotides. The derived amino acid sequence of ovine pre-alpha-lactalbumin differs from that of its bovine counterpart by 8 amino acid substitutions, all but one originating from single mutations. Comparison of sequences of guinea pig, rat and human alpha-lactalbumin mRNAs with their ovine and bovine counterparts has revealed that these molecules have rapidly evolved. The highest degree of conservation was observed in the region coding for the mature protein and corresponds essentially to sequences which interact with UDP-galactosyltransferase and Ca2+ ions.  相似文献   

16.
The nucleotide sequence of a cDNA clone (pML10) for chicken cardiac myosin light chain is described. The cDNA insert contains 613 nucleotides representing the entire coding sequence, with the exception of nine NH2-terminal amino acids, and the full 3'-non-coding region of 146 nucleotides. The missing 5' terminus of the mRNA, not represented in the clone pML10, was obtained by extension of the cDNA using a 43 nucleotide long internal EcoR1 fragment as a primer. The non-coding region contains several direct and inverted repeated sequences and the polyadenylation signal sequence AATAAA. The coding portion exhibits non-random usage of synonymous codons with a strong bias for codons ending in G and C.  相似文献   

17.
Structure of the black beetle virus genome and its functional implications   总被引:20,自引:0,他引:20  
The black beetle virus (BBV) is an isometric insect virus whose genome consists of two messenger-active RNA molecules encapsidated in a single virion. The nucleotide sequence of BBV RNA1 (3105 bases) has been determined, and this, together with the sequence of BBV RNA2 (1399 bases) provides the complete primary structure of the BBV genome. The RNA1 sequence encompasses a 5' non-coding region of 38 nucleotides, a coding region for a protein of predicted molecular weight 101,873 (protein A, implicated in viral RNA synthesis) and a 3' proximal region encoding RNA3 (389 bases), a subgenomic messenger RNA made in infected cells but not encapsidated into virions. The RNA3 sequence starts 16 bases inside the coding region of protein A and contains two overlapping open reading frames for proteins of molecular weight 10,760 and 11,633, one of which is believed to be protein B, made in BBV-infected cells. A limited homology exists between the sequences of RNA1 and RNA2. Sequence regions have been identified that provide energetically favorable bonding between RNA2 and RNA1 possibly to facilitate their common encapsidation, and between RNA2 and negative strand RNA1 possibly to regulate the production of RNA3.  相似文献   

18.
We present fine mapping of a cis-acting nucleotide sequence found in the 5' region of yellow fever virus genomic RNA that is required for RNA replication. There is evidence that this sequence interacts with a complementary sequence in the 3' region of the genome to cyclize the RNA. Replicons were constructed that had various deletions in the 5' region encoding the capsid protein and were tested for their ability to replicate. We found that a sequence of 18 nucleotides (residues 146 to 163 of the yellow fever virus genome, which encode amino acids 9 to 14 of the capsid protein) is essential for replication of the yellow fever virus replicon and that a slightly longer sequence of 21 nucleotides (residues 146 to 166, encoding amino acids 9 to 15) is required for full replication. This region is larger than the core sequence of 8 nucleotides conserved among all mosquito-borne flaviviruses and contains instead the entire sequence previously proposed to be involved in cyclization of yellow fever virus RNA.  相似文献   

19.
20.
Primary structure of a genomic zein sequence of maize.   总被引:13,自引:7,他引:6       下载免费PDF全文
The nucleotide sequence of a genomic clone (termed Z4 ) of the zein multigene family was compared to the nucleotide sequence of related cDNA clones of zein mRNAs. A tandem duplication of a 96-bp sequence is found in the genomic clone that is not present in the related cDNA clones. When the duplication is disregarded, the nucleotide sequence homology between Z4 and its related cDNAs was approximately 97%. The nucleotide sequence is also compared to other isolated cDNAs. No introns in the coding region of the zein gene are detected. The first nucleotide of a putative TATA box, TATAAATA , was located 88 nucleotides upstream of the first nucleotide of the first ATG codon which initiated the open reading frame. The first nucleotide of a putative CCAAT box, CAAAAT , appeared 45 nucleotides upstream of the first nucleotide of the zein cDNA clones in the 3' non-coding region also appeared in the genomic sequence at the same locations. The amino acid composition of the polypeptide specified by the Z4 nucleotide sequence is similar to the known composition of zein proteins.  相似文献   

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