We report the nucleotide and derived amino acid sequence of the ATPase 1 gene from Plasmodium falciparum. The amino acid sequence shares homology with the family of "P"-type cation translocating ATPases in conserved regions important for nucleotide binding, conformational change, or phosphorylation. The gene, which is present on chromosome 5, has a product longer than any other reported for a P-type ATPase. Interstrain analysis from 12 parasite isolates by the polymerase chain reaction reveals that a 330-bp nucleotide sequence encoding three cytoplasmic regions conserved in cation ATPases (regions a-c) is of constant length. By contrast, another 360-bp sequence which is one of four regions we refer to as "inserts" contains arrays of tandem repeats which show length variation between different parasite isolates. Polymorphism results from differences in the number and types of repeat motif contained in this insert. Inserts are divergent in sequence from other P-type ATPases and share features in common with many malarial antigens. Studies using RNA from the erythrocytic stages of the malarial life cycle suggest that ATPase 1 (including the sequence which encodes tandem repeats) is expressed at the large ring stage of development. Immunolocalization has identified ATPase 1 to be in the region of the parasite plasma membrane and pigment body. These findings suggest a possible model for the genesis of malarial antigens. 相似文献
The nucleotide sequence of the variant of human immunodeficiency virus of type 1 (HIV-1), mostly widespread on the territory of the Novosibirsk region, was determined. The analysis of the nucleotide sequence confirmed that this variant belonged to HIV-1 of subtype A. The HIV-1 recombinant variant of subtype envB/envA with the recombination area within the second conservative region C2 of gene env, so far unknown, was detected and characterized. In HIV-1 the area at the beginning of gene env (5'-env) was found to belong to subtype B and the sequence at the end of gene env (3'-env), to subtype A. The analysis of the amino acid sequence of the third variable region of gene env demonstrated that the viruses under study belonged to macrophagotropic "slow/low" variants, characterized by low replication speed. The analysis of nucleotide sequences of the isolated variants of HIV-1 revealed their close genetic relationship with HIV-1 isolates circulating on the territory of Ukraine. 相似文献
The primary nucleotide sequence of Novikoff hepatoma ascites cell 5.8S rRNA (also known as 5.5 or 7S RNA) has been determined to be: This sequence is 75% homologous with the primary nucleotide sequence of yeast 5.8S rRNA and 100% homologous with oligonucleotide marker fragments from HeLa cell RNA. In constrast, only limited homology is evident with oligonucleotides from 5.8S RNA of several flowering plants and many of the characteristic fragments differ. 相似文献
A child was found to be excreting type 1 vaccine-derived poliovirus (VDPV) with a 1.1% sequence drift from Sabin type 1 vaccine strain in the VP1 coding region 6 months after he was immunized with oral live polio vaccine. Seventeen type 1 poliovirus isolates were recovered from stools taken from this child during the following 4 months. Contrary to expectation, the child was not deficient in humoral immunity and showed high levels of serum neutralization against poliovirus. Selected virus isolates were characterized in terms of their antigenic properties, virulence in transgenic mice, sensitivity for growth at high temperatures, and differences in nucleotide sequence from the Sabin type 1 strain. The VDPV isolates showed mutations at key nucleotide positions that correlated with the observed reversion to biological properties typical of wild polioviruses. A number of capsid mutations mapped at known antigenic sites leading to changes in the viral antigenic structure. Estimates of sequence evolution based on the accumulation of nucleotide changes in the VP1 coding region detected a "defective" molecular clock running at an apparent faster speed of 2.05% nucleotide changes per year versus 1% shown in previous studies. Remarkably, when compared to several type 1 VDPV strains of different origins, isolates from this child showed a much higher proportion of nonsynonymous versus synonymous nucleotide changes in the capsid coding region. This anomaly could explain the high VP1 sequence drift found and the ability of these virus strains to replicate in the gut for a longer period than expected. 相似文献
Analysis and comparison of mutation spectra is one of the major tasks of molecular biology, since mutation spectra often reveal important properties of various mutagens and proteins involved in the repair/replication systems. Mutability is known to vary significantly along the nucleotide sequence. Mutations are abundant at certain positions (mutation hotspots). In this work, we applied regression analysis based on the basic logic patterns to understand the role of the nucleotide sequence context in mutation induction. The spectra of mutations induced by various alkylating agents were studied. The nucleotide bases at positions –2, –1, +1 and +2 were shown to have the most significant effect in G : C A : T replacements. 相似文献
pSTNV-1 is a chimera plasmid that contains a nearly full-size double-stranded DNA copy of the satellite tobacco necrosis virus RNA genome (see preceding paper by van Emmelo et al., 1980) and we report here the complete nucleotide sequence of this STNV2 DNA insert. The results show that except for 23 nucleotide pairs corresponding to the 5′ end of STNV RNA, a full-size STNV DNA copy is present in pSTNV-1. The total nucleotide sequence of the STNV genome contains 1239 residues. The amino acid sequence of the coat protein can be deduced from the 5′ half of the DNA message strand and shows a rather hydrophobic carboxyl-terminal region and a basic amino-terminal region. The 3′ untranslated part of the viral RNA is 622 nucleotides long. A secondary structure model for the 5′ end showing an interaction with a segment in the 3′ half is proposed. The 3′ end region can be folded into a transfer RNA cloverleaf-like structure with an anticodon for AUG. 相似文献
The sequence of the 2227 nucleotides of the 3-terminus of chilli vein-banding mottle virus-Chiangmai isolate (CVbMV-CM1) genome was determined. This sequence encodes a putative 287 amino acid coat protein. Downstream of coat protein coding region is a 288 nucleotide untranslated sequence terminated by a polyadenylate tract. The amino acid sequence of coat protein contained aspartic acid–alanine–glycine tripeptide, which may correlate with the high frequency of aphid transmissibility. The cleavage site between large nuclear inclusion protein (NIB) and coat protein was glutamine/serine. Comparison of 3 non-coding region nucleotide and coat protein amino acid sequences of CVbMV-CM1 with those of other 18 potyviruses showed 44–56% and 54–65% homology respectively, suggesting CVbMV should be regarded as new potyvirus. 相似文献
The nucleotide sequence of a cDNA coding for the human acylaminoacid-releasing enzyme (AARE, also known as acylpeptide hydrolase)[EC 3.4.19.1] subunit has been determined. The amino acid sequenceof human AARE subunit deduced from its cDNA nucleotide sequenceshowed a high degree of identity (91.5%) with both the correspondingproteins from the pig and the rat. The AARE cDNA shows 99.2%identity with a 3.3 kb cDNA transcribed from a locus (DNF15S2)on the short arm of human chromosome 3, whose deletion is associatedwith small cell lung cancer, taking into consideration thatthe sequence of the 3.3-kb cDNA previously reported was causedby misreading. 相似文献
A cDNA clone (pBLT63) encoding a protein synthesis elongation factor 1 (EF-1) was isolated from a low-temperature winter barley shoot meristem library by differential screening. The nucleotide sequence of the coding region of the low-temperature-induced barley gene shows very high homology with two EF-1 plant genes from tomato and Arabidopsis. The barley genome contains an EF-1 gene family situated on the short arm of chromosome 2 and the long arm of chromosome 5. The nucleotide sequence data reported will appear in the EMBL, GenBank and DDBJ Nucleotide Sequence Databases under the accession number Z23130. 相似文献
The multigene family encoding the small subunit polypeptides of ribulose-1,5-bisphosphate carboxylase/oxygenase in the crucifer Arabidopsis thaliana has been isolated and the organization and structure of the individual members determined. The family consists of four genes which have been divided into two subfamilies on the basis of linkage and DNA and amino acid sequence similarities. Three of the genes, designated ats1B, ats2B, and ats3B, reside in tandem on an 8 kb stretch of the chromosome. These genes share greater than 95% similarity in DNA sequence and encode polypeptides identical in length and 96.7% similar in amino acid sequence. The fourth gene, ats1A, is at least 10 kb removed from, or completely unlinked to the B subfamily. The B subfamily genes are more similar to each other than to ats1A in nucleotide and amino acid sequence. All four genes are interupted by two introns whose placement within the coding region of the genes is conserved. The introns of the B subfamily genes are similar in length and nucleotide sequence, but show no similarity to the introns of ats1A. Comparison of the DNA sequences within the immediate 5 and 3 flanking sequences among the genes revealed only limited regions of homology. S1 analysis shows that all four genes are expressed. 相似文献
We analyzed the possibility of triplex formation in the human 1-antitrypsin gene. Conditions and nucleotide sequence dependence of triplex formation and thermostability of the product were determined. 相似文献
The nucleotide sequence of 32P-RNA from Q beta phage clones was sampled by two-dimensional polyacrylamide gel electrophoresis of the RNAase T1-resistant oligonucleotides (T1 fingerprinting). About 15% of the clones derived from a multiply passaged Q beta population showed fingerprint patterns which deviated from that of the RNA from the total population. All deviations examined could be attributed to one and, less frequently, to two or more nucleotide transitions. Since the fingerprinting technique allows the analysis of only about 10% of the RNA sequence, we estimate that each viable phage genome in a multiply passaged population differs in one to two positions from the "average" sequence of the parental population. Several deviant clones were tested by growth competition against a "wildtype" population, after 10-20 generations, the resulting phage showed the "wild-type" T1 fingerprint pattern. We propose that a Q beta phage population is in a dynamic equilibrium, with viable mutants arising at a high rate (Batschelet, Domingo and Weissmann, 1976; Domingo, Flavell and Weissmann, 1976) on the one hand, and being strongly selected against on the other. The genome of Q beta phage cannot be described as a defined unique structure, but rather as a weighted average of a large number of different individual sequences. 相似文献
Inbred rat strains provide a rich source of genetic diversity in immunologically relevant gense. We have characterized the alleles of one of these genes, encoding the rat T-cell receptor C1 chain, by Southern blots and nucleic acid sequencing. The Cb1 gene segments from DA and LEW rats display complex allotypic variation: both coding and noncoding regions contain multiple nucleotide substitutions. In addition, there is a polymorphic insertion of a rat repetitive LINE element 3 to the coding region. The Cb1 alleles are one part of larger Tcrb haplotypes, containing V, D, and J elements; complete Cb1 genomic nucleotide sequences, and a partial list of the strain distribution of the two alleles, are described in this report.The nucleotide sequence data reported in this paper have been submitted to the GenBank nucleotide sequence database and have been assigned the accession number M65136. 相似文献
Tnr1 is a repetitive sequence in rice with several features characteristic of a transposable DNA element. Its copy number was estimated to be about 3500 per haploid genome by slot-blot hybridization. We have isolated six members of Tnr1 located at different loci by PCR (polymerase chain reaction) and determined their nucleotide sequences. The Tnr1 elements were similar in size and highly homologous (about 85%) to the Tnr1 sequence identified first in the Waxy gene in Oryza glaberrima. A consensus sequence of 235 by could be derived from the nucleotide sequences of all the Tnr1 members. The consensus sequence showed that base substitutions occurred frequently in Tnr1 by transition, and that Tnr1 has terminal inverted repeat sequences of 75 bp. Almost all the chromosomal sequences that flank the Tnr1 members were 5-PuTA-3 and 5-TAPy-3, indicating that Tnr1 transposed to 5-PuTAPy-3 sites, duplicating the TA sequence. PCR-amplified fragments from some rice species did not contain the Tnr1 members at corresponding loci. Comparison of nucleotide sequences of the fragments with or without a Tnr1 member confirmed preferential transposition of Tnr1 to 5-PuTAPy-3 sites, duplicating the TA sequence. One amplified sequence suggested that imprecise excision had occurred to remove a DNA segment containing a Tnr1 member and its neighboring sequences at the Waxy locus of rice species with genome types other than AA. We also present data that may suggest that Tnr1 is a defective form of an autonomous transposable element. 相似文献