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PubMedDate not supplied

[Determination of the taxonomic position of bacteria from Lake Baikal using sequence analysis of 16S rRNA fragments].

The taxonomic position of seven strains of aquatic bacteria from Lake Baikal was determined based on the analysis of the nucleotide sequences of 16 S rRNA gene fragments. Three strains belonged to the gamma-sub-class of Proteobacteria, one strain, to the beta-subclass, and the other three stains were assigned to the genus Bacillus (gram-positive bacteria with a low G+C content).

Bacillus↗

PubMed1995

Sequence analysis of a 9873 bp fragment of the left arm of yeast chromosome XV that contains the ARG8 and CDC33 genes, a putative riboflavin synthase beta chain gene, and four new open reading frames.

The DNA sequence of a 9873 bp fragment located near the left telomere of chromosome XV has been determined. Sequence analysis reveals seven open reading frames. One is the ARG8 gene coding for N-acetylornithine aminotransferase. Another corresponds to CDC33, which codes for the initiation factor 4E or cap binding protein. The open reading frame AOE169 can be considered as the putative gene for the Saccharomyces cerevisiae riboflavin synthase beta chain, since its translation product shows strong homology with four prokaryotic riboflavin synthase beta chains.

Amino Acid Sequence↗

PubMed2024

The Hunt Lab Guide to De Novo Peptide Sequence Analysis by Tandem Mass Spectrometry.

Donald Hunt has made seminal contributions to the fields of proteomics, immunology, epigenetics, and glycobiology. The foundation of every important work to come out of the Hunt Laboratory is de novo peptide sequencing. For decades, he taught hundreds of students, postdocs, engineers, and scientists to directly interpret mass spectral data. To honor his legacy and ensure that the art of de novo sequencing is not lost, we have adapted his teaching materials into "The Hunt Lab Guide to De Novo Peptide Sequence Analysis by Tandem Mass Spectrometry". In addition to the de novo sequencing tutorials, we present two freely available software tools that facilitate manual interpretation of mass spectra and validation of search results. The first, "Hunt Lab Peptide Fragment Calculator", calculates precursor and fragment mass-to-charge ratios for any peptide. The second program, "Predator Protein Fragment Calculator", was inspired in part by the fragment calculator developed in the Hunt Lab. Its capabilities are enhanced to facilitate interpretation of mass spectral data derived from intact proteins. We hope that the combination of these educational tools will continue to benefit students and researchers by empowering them to interpret data on their own.

Tandem Mass Spectrometry↗

PubMed1992

CDC14 of Saccharomyces cerevisiae. Cloning, sequence analysis, and transcription during the cell cycle.

We have cloned, mapped and sequenced the complete CDC14 gene of Saccharomyces cerevisiae and characterized its transcription during the cell cycle. CDC14 was found within a 3.5-kilobase pair XhoI-XbaI fragment of chromosome VI. The DNA sequence reveals an open reading frame capable of encoding a 423-amino acid polypeptide. Protein sequence comparisons through the Prosite, GenBank and EMBL databases allowed us to identify a conserved protein tyrosine phosphatase active site in the encoded CDC14 protein beginning at amino acid 153. Disruption demonstrates that CDC14 is an essential gene. The level of the CDC14 transcript appears to be weakly cell cycle-regulated and has a periodicity which lags approximately 15 min behind histone HTB1 mRNA accumulation levels. DNA sequence analysis has identified a region within the CDC14 promoter which bears a striking resemblance (15 out of 21 base pairs identity) to the cell cycle regulation region of the promoter of the histone H2A1-H2B1 (HTA1-HTB1) gene pair. The cell cycle regulation sequence is responsible for the periodic accumulation and hydroxyurea sensitivity of the histone HTA1-HTB1 message. However, unlike histone mRNA, which is repressed upon hydroxyurea arrest, CDC14 mRNA appears to be unaffected. This suggests that CDC14 and histone genes are regulated by different mechanisms during the cell cycle. Furthermore, superhelical density measurements suggest that CDC14 is not involved in nucleosome assembly.

Amino Acid Sequence↗

PubMed1995

Sequence analysis of the phs operon in Salmonella typhimurium and the contribution of thiosulfate reduction to anaerobic energy metabolism.

The phs chromosomal locus of Salmonella typhimurium is essential for the dissimilatory anaerobic reduction of thiosulfate to hydrogen sulfide. Sequence analysis of the phs region revealed a functional operon with three open reading frames, designated phsA, phsB, and phsC, which encode peptides of 82.7, 21.3, and 28.5 kDa, respectively. The predicted products of phsA and phsB exhibited significant homology with the catalytic and electron transfer subunits of several other anaerobic molybdoprotein oxidoreductases, including Escherichia coli dimethyl sulfoxide reductase, nitrate reductase, and formate dehydrogenase. Simultaneous comparison of PhsA to seven homologous molybdoproteins revealed numerous similarities among all eight throughout the entire frame, hence, significant amino acid conservation among molybdoprotein oxidoreductases. Comparison of PhsB to six other homologous sequences revealed four highly conserved iron-sulfur clusters. The predicted phsC product was highly hydrophobic and similar in size to the hydrophobic subunits of the molybdoprotein oxidoreductases containing subunits homologous to phsA and phsB. Thus, phsABC appears to encode thiosulfate reductase. Single-copy phs-lac translational fusions required both anaerobiosis and thiosulfate for full expression, whereas multicopy phs-lac translational fusions responded to either thiosulfate or anaerobiosis, suggesting that oxygen and thiosulfate control of phs involves negative regulation. A possible role for thiosulfate reduction in anaerobic respiration was examined. Thiosulfate did not significantly augment the final densities of anaerobic cultures grown on any of the 18 carbon sources tested. on the other hand, washed stationary-phase cells depleted of ATP were shown to synthesize small amounts of ATP on the addition of the formate and thiosulfate, suggesting that the thiosulfate reduction plays a unique role in anaerobic energy conservation by S typhimurium.

Amino Acid Sequence↗

PubMed1995

Partial amino acid sequence of an L-amino acid oxidase from the cyanobacterium Synechococcus PCC6301, cloning and DNA sequence analysis of the aoxA gene.

A novel type of L-amino acid oxidase from Synechococcus PCC6301 was purified and subjected to amino acid sequence analysis. Since the N-terminus of the L-amino acid oxidase protein was not accessible for Edman degradation, the protein was partially hydrolysed and a contiguous sequence of 17 amino acid residues was obtained from an endogenous peptide fragment. Based on the partial peptide sequence two oligonucleotides were designed, which were used as probes in Southern hybridization experiments in order to identify the corresponding aoxA gene. The aoxA gene was isolated from a size-fractionated genomic library of Synechococcus PCC6301 and subsequently sequenced. From the nucleotide sequence (data base accession number Z48565) it can be deduced that the L-amino acid protein consists of 355 amino acid residues resulting in a molar mass of 39.2 kDa. The calculated isoelectric point of the protein is 9.81. The L-amino acid oxidase from Synechococcus PCC6301 shows low homologies to other flavin oxidases/dehydrogenases, especially amine oxidases, but no homologies to other so far sequenced L- or D-amino acid oxidases.

Amino Acid Oxidoreductases↗

PubMed1986

Cloning and sequence analysis of cDNA for mouse prolactin.

The present study was undertaken to find out whether or not sexual dimorphism in biological activities and amino acid compositions of mouse prolactin might be due to heterogeneity in mRNA for mouse prolactin Cloned cDNAs for mouse prolactin were first isolated from a mouse pituitary cDNA library by hybridization with a rat prolactin cDNA. Then, one clone of about 140 positive clones obtained from 2000 transformants was subjected to nucleotide sequence analysis and verified to contain a nearly full length of cDNA sequence coding for mouse prolactin precursor. The deduced complete amino acid sequence indicates that the precursor molecule consists of 31 amino acids as the signal peptide and 197 amino acids of prolactin, in which two amino acids were found to be different from the amino acid sequence previously published elsewhere. S1 nuclease mapping analysis using male and female pituitary RNAs indicates that mouse preprolactin is encoded by two mRNAs in both sexes. The two mRNAs differ from each other based upon the deletion of three nucleotides in the coding region for the signal peptide determined by the nucleotide sequence analysis in other cDNA clones. In the present study, no sexual difference was revealed in murine prolactin mRNA.

Amino Acid Sequence↗

PubMed2003

[Sequence analysis of bacterial transposon in NHX gene of Populus euphratica].

The United Nations Environment Program estimates that approximately 20% of agricultural land and 50% of cropland in the world is salt-stressed. The gene NHX (Na+/H+ exchanger) encodes functional protein that catalyzes the countertransport of Na+ and H+ across membranes and may play an important role in plant salt tolerance. To clone the NHX from the wild plant Populus euphratica collected in Tarim basin and Xinjiang Wujiaqu district into a T-vector, designed primer was used to amplify 1kb NHX cDNA fragment with RT-PCR. Total RNA was extracted from Populus euphratica tissue (plant tissue was collected from Tarim basin and Xinjiang Wujiaqu district and stored in liquid nitrogen) according to the Plant RNA Mini Kits of Omega. First cDNAs were synthesized from 1 microg total RNA of Populus euphratica seedling. A pair of primers were used to perform RT-PCR. The amplified DNA fragment was purified and cloned into pMD18-T vector. However, 1kb and 2.3kb fragment were obtained from Tarim basin and Xinjiang Wujiaqu district and named as PtNHX and PwNHX, respectively. Sequence analysis reveals that the cloned PtNHX fragment of Populus euphratica contains partial NHX coding region with 98%, 86%, 84% and 80% identity comparing with Atriplex gemelini, Suaeda maritima, Arabidopsis thaliana and Oryza sativa, respectively. This analysis suggests that NHX gene would be highly conserved in terms of evolution in plant; and it also suggests that the NHX gene of Populus euphratica also would have the similarity with that of Arabidopsis. It may be of great importance in improvement of the plant salt tolerance and breed of crop. At the same time, sequence analysis shows that PwNHX gene includes a coding region about 1350bp with 99% identity comparing with transposon Tn10 IS10-left transposase of Shigella flexneri. On the one hand, the NHX gene may lose its function because it was inserted a fragment in coding region. On the other hand, its product may play a important role in salt tolerance. Populus grow in saline soil. It speculates that it may have other salt tolerance mechanism in Populus. The transposon can be used as transposon tagging to clone other genes and it will help us to understand farther the salt tolerance mechanism.

Amino Acid Sequence↗

PubMed1978

Sequence analysis of 5'[32P] labeled mRNA and tRNA using polyacrylamide gel electrophoresis.

Sequence analysis of 5'-[32P] labeled tRNA and eukaryotic mRNA using an adaptation of a method recently described by Donis-Keller, Maxam and Gilbert for mapping guanines, adenines and pyrimidines from the 5'-end of an RNA is described. In addition, a technique utilizing two-dimensional polyacrylamide gel electrophoresis for identification of pyrimidines within a sequence is described. 5'-[32P] Labeled rabbit beta-globin mRNA and N. crassa mitochondrial initiator tRNA were partially digested with T1- RNase for cleavage at G residues, with U2-RNase for cleavage at A residues, with an extracellular RNase from B. cereus for cleavage at pyrimidine residues and with T2-RNase or with alkali for cleavage at all four residues. The 5'-[32P] labeled partial digestion products were separated according to their size, by electrophoresis in adjacent lanes of a polyacrylamide slab gel and the location of G's, A's and of pyrimidines extending 60-80 nucleotides from the 5'-end of the RNA determined. Two-dimensional polyacrylamide gel electrophoresis was used to separate the 5'-[32P] labeled fragments present in partial alkali digests of a 5'-[32P] labeled mRNA. The mobility shifts corresponding to the difference of a C residue were distinct from those corresponding to a U residue and this formed the basis of a method for distinguishing between the pyrimidines.

Animals↗

PubMed1985

Isolation and sequence analysis of a cDNA clone encoding the fifth complement component.

We have used available protein sequence data for the anaphylatoxin (C5a) portion of the fifth component of human complement (residues 19-25) to synthesize a mixed-sequence oligonucleotide probe. The labeled oligonucleotide was then used to screen a human liver cDNA library, and a single candidate cDNA clone of 1.85 kilobase pairs was isolated. Hybridization of the mixed-sequence probe to the complementary strand of the plasmid insert and sequence analysis by the dideoxy method predicted the expected protein sequence of C5a (positions 1-12), amino-terminal to the anticipated priming site. The sequence obtained further predicted an arginine-rich sequence (RPRR) immediately upstream of the N-terminal threonine of C5a, indicating that the promolecule form of C5 is synthesized with a beta alpha-chain orientation as previously shown for pro-C3 and pro-C4. The C5 cDNA clone was sheared randomly by sonication, subcloned into M13 mp8, and sequenced at random by the dideoxy technique, thereby generating a contiguous sequence of 1703 base pairs. This clone contained coding sequence for the C-terminal 262 amino acid residues of the beta-chain, the entire C5a fragment, and the N-terminal 98 residues of the alpha'-chain. The 3' end of the clone had a polyadenylated tail preceded by a polyadenylation recognition site, a 3'-untranslated region, and base pairs homologous to the human Alu concensus sequence. Comparison of the derived partial human C5 protein sequence with that previously determined for murine C3 and human alpha 2-macroglobulin has indicated regions of pronounced sequence similarity. Examination of cytoplasmic RNA prepared from human liver and the human hepatoma cell line Hep G2 by Northern transfer has indicated a C5 mRNA species of about 5.2 kilobase pairs.

Adult↗

PubMed1998

Automating the identification of DNA variations using quality-based fluorescence re-sequencing: analysis of the human mitochondrial genome.

Diagnostic re-sequencing plays a central role in medical and evolutionary genetics. In this report we describe a process that applies fluorescence-based re-sequencing and an integrated set of analysis tools to automate and simplify the identification of DNA variations using the human mitochondrial genome as a model system. Two programs used in genome sequence analysis (Phred, a base-caller, and Phrap, a sequence assembler) are applied to assess the quality of each base call across the sequence. Potential DNA variants are automatically identified and 'tagged' by comparing the assembled sequence with a reference sequence. We also show that employing the Consed program to display a set of highly annotated reference sequences greatly simplifies data analysis by providing a visual database containing information on the location of the PCR primers, coding and regulatory sequences and previously known DNA variants. Among the 12 genomes sequenced 378 variants including 29 new variants were identified along with two heteroplasmic sites, automatically detected by the PolyPhred program. Overall we document the ease and speed of performing high quality and accurate fluorescence-based re-sequencing on long tracts of DNA as well as the application of new approaches to automatically find and view DNA variants among these sequences.

Base Sequence↗

PubMed2001

Identification of mesoderm development (mesd) candidate genes by comparative mapping and genome sequence analysis.

The proximal albino deletions identify several functional regions on mouse Chromosome 7 critical for differentiation of mesoderm (mesd), development of the hypothalamus neuroendocrine lineage (nelg), and function of the liver (hsdr1). Using comparative mapping and genomic sequence analysis, we have identified four novel genes and Il16 in the mesd deletion interval. Two of the novel genes, mesdc1 and mesdc2, are located within the mesd critical region defined by BAC transgenic rescue. We have investigated the fetal role of genes located outside the mesd critical region using BAC transgenic complementation of the mesd early embryonic lethality. Using human radiation hybrid mapping and BAC contig construction, we have identified a conserved region of human chromosome 15 homologous to the mesd, nelg, and hsdr1 functional regions. Three human diseases cosegregate with microsatellite markers used in construction of the human BAC/YAC physical map, including autosomal dominant nocturnal frontal lobe epilepsy (ENFL2; also known as ADNFLE), a syndrome of mental retardation, spasticity, and tapetoretinal degeneration (MRST); and a pyogenic arthritis, pyoderma gangrenosum, and acne syndrome (PAPA).

Abnormalities, Multiple↗

PubMed1995

Genomic mapping and sequence analysis of the fowl adenovirus serotype 10 hexon gene.

The gene for the major capsid protein (hexon) of fowl adenovirus serotype 10 (FAV-10) has been identified by the use of the expression vector pGEX and rabbit polyclonal antisera raised against FAV-10. The nucleotide sequence of the entire hexon gene has been determined. Sequence analysis revealed an open reading frame of 2808 bp coding for a putative polypeptide 936 amino acids long with a molecular mass of 105.5 kDa. The translation initiation codon has a local sequence which conforms with the optimal translation start sequence of CC(A/G)CCATGG. The location of the hexon gene in the FAV genome was from 46.85 to 52.81 map units, which is to the left of the hexon gene in the genomes of both bovine and human adenovirus (52.4 to 60.5 map units.). A splice acceptor site was identified 12 bp upstream of the initiation codon by using mRNA and PCR. It had the sequence TAGG which conforms to the consensus sequence of (C/T)AGG. Comparison of the amino acid sequence of the FAV-10 hexon with those of the bovine, human and murine hexon gene products revealed highest levels of identity occurring in the regions corresponding to the pedestals which form the base region of the hexon, and the lowest levels of identity in the regions corresponding to the loops which are exposed to the external environment.

Amino Acid Sequence↗

PubMed2006

A neural network-based novelty detector for image sequence analysis.

This paper proposes a new model of "novelty detection" for image sequence analysis using neural networks. This model uses the concept of artificially generated negative data to form closed decision boundaries using a multilayer perceptron. The neural network output is novelty filtered by thresholding the output of multiple networks (one per known class) to which the sample is input and clustered for determining which clusters represent novel classes. After labeling these novel clusters, new networks are trained on this data. We perform experiments with video-based image sequence data containing a number of novel classes. The performance of the novelty filter is evaluated using two performance metrics and we compare our proposed model on the basis of these with five baseline novelty detectors. We also discuss the results of retraining each model after novelty detection. On the basis of Chi-square performance metric, we prove at 5 percent significance level that our optimized novelty detector performs at the same level as an ideal novelty detector that does not make any mistakes.

Algorithms↗

PubMed1992

Estimates of gene flow in Drosophila pseudoobscura determined from nucleotide sequence analysis of the alcohol dehydrogenase region.

The genetic structure of Drosophila pseudoobscura populations was inferred from a nucleotide sequence analysis of a 3.4-kb segment of the alcohol dehydrogenase (Adh) region. A total of 99 isochromosomal strains collected from 13 populations in North and South America were used to determine if any population departed from a neutral model and to estimate levels of gene flow between populations. This study also included the nucleotide sequences from two sibling species, D. persimilis and D. miranda. We estimated the neutral mutation parameter, 4N mu, in synonymous and noncoding sites for 17 subregions of Adh in each of nine populations with sample sizes greater than three. The nucleotide diversity data in the nine populations was tested for departures from an equilibrium neutral model with two statistical tests. The Tajima and the Hudson, Kreitman, Aguade tests showed that each population fails to reject a neutral model. Tests for genetic differentiation between populations fail to show any population substructure among the North American populations of D. pseudoobscura. The nucleotide diversity data is consistent with direct and indirect measures of gene flow that show extensive dispersal between populations of D. pseudoobscura.

Alcohol Dehydrogenase↗

PubMed1999

Sequence analysis and genetic classification of tick-borne encephalitis viruses from Europe and Asia.

The epidemiology of tick-borne encephalitis virus was investigated by comparative sequence analysis of virus strains isolated in endemic areas of Europe and Asia. Phylogenetic relationships were determined from the nucleotide and amino acid sequences of the major envelope (E) protein of 16 newly sequenced strains and nine previously published sequences. Three genetic lineages could be clearly distinguished, corresponding to a European, a Far Eastern and a Siberian subtype. Amino acids characteristic for each of the subtypes ('signature' amino a cids) were identified and their location in the atomic structure of protein E was determined. The degree of variation between strains within subtypes was low and exhibited a maximum of only 2.2% at the amino acid level. A maximum difference of 5.6% was found between the three subtypes, which is in the range of variation reported for other flaviviruses.

Amino Acid Sequence↗

PubMed1994

Nucleotide sequence analysis of 77.7 kb of the human V beta T-cell receptor gene locus: direct primer-walking using cosmid template DNAs.

The nucleotide sequence of 77.7 kb from the human T-cell receptor beta-chain locus was determined directly from three overlapping cosmid clones using the primer-walking approach. Computer-aided analyses of this sequence reveal the presence of at least 11 genic regions that are closely related to the human T-cell receptor beta variable region (TCRBV) gene family. These include five germline sequences that have previously been determined, V beta 21.2, V beta 8.1, V beta 8.2, V beta 8.3, and V beta 16, and four whose sequences have partially been determined at the mRNA level, V beta 6, V beta 23, V beta 12.2, V beta 24. The two remaining V beta Tcr-related sequences have eluded discovery by cDNA and RT-PCR cloning and genomic blot hybridization methods. These two V beta Tcr-related genes lack > 75% nucleotide sequence identity with any other V beta Tcr gene member and therefore, by convention, are referred to as new subfamily members V beta 25 and V beta 26. This lack of shared identity with other subfamily members explains why they were not detected by hybridization. The promoter regions of these V beta Tcr genes contain the conserved Tcr decamer element located between 80 and 110 bp 5' of the translation start site, generally near a putative TATAA promoter element. Our sequence analysis also reveals that a 3.3-kb duplication unit was involved in the recombination event that produced the closely related V beta 8.1 and 8.2 gene subfamily members. This sequenced region of the V beta locus contains an average number of repetitive DNA elements (21 Alu, three L1, three MER, and three retrovirus-related elements.

Amino Acid Sequence↗

PubMed1997

DNA sequence analysis of Sry alleles (subgenus Mus) implicates misregulation as the cause of C57BL/6J-Y(POS) sex reversal and defines the SRY functional unit.

The Sry (sex determining region, Y chromosome) open reading frame from mice representing four species of the genus Mus was sequenced in an effort to understand the conditional dysfunction of some M. domesticus Sry alleles when present on the C57BL/6J inbred strain genetic background and to delimit the functionally important protein regions. Twenty-two Sry alleles were sequenced, most from wild-derived Y chromosomes, including 11 M. domesticus alleles, seven M. musculus alleles and two alleles each from the related species M. spicilegus and M. spretus. We found that the HMG domain (high mobility group DNA binding domain) and the unique regions are well conserved, while the glutamine repeat cluster (GRC) region is quite variable. No correlation was found between the predicted protein isoforms and the ability of a Sry allele to allow differentiation of ovarian tissue when on the C57BL/6J genetic background, strongly suggesting that the cause of this sex reversal is not the Sry protein itself, but rather the regulation of SRY expression. Furthermore, our interspecies sequence analysis provides compelling evidence that the M. musculus and M. domesticus SRY functional domain is contained in the first 143 amino acids, which includes the HMG domain and adjacent unique region (UR-2).

Alleles↗