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PubMed1985

Genes 55, alpha gt, 47 and 46 of bacteriophage T4: the genomic organization as deduced by sequence analysis.

The nucleotide sequence of T4 genes 55, alpha gt, 47 and 46 was determined by a combination of 'classical' procedures and a shotgun approach. Small DNA fragments generated by frequent cleavage with restriction enzymes or by sonication of restriction fragments were cloned in phage M13 vectors and sequenced by the dideoxy method. The positions of the genes were determined by marker rescue between the corresponding T4 amber mutants and the cloned T4 DNA fragments used in the sequencing experiments. The sequence gives an insight into the organization of this 7.1-kb early region of the T4 genome and shows that genetically 'silent' portions within this region are not void of genetic information.

Base Sequence↗

PubMed1989

Coronavirus genome: prediction of putative functional domains in the non-structural polyprotein by comparative amino acid sequence analysis.

Amino acid sequences of 2 giant non-structural polyproteins (F1 and F2) of infectious bronchitis virus (IBV), a member of Coronaviridae, were compared, by computer-assisted methods, to sequences of a number of other positive strand RNA viral and cellular proteins. By this approach, juxtaposed putative RNA-dependent RNA polymerase, nucleic acid binding ("finger"-like) and RNA helicase domains were identified in F2. Together, these domains might constitute the core of the protein complex involved in the primer-dependent transcription, replication and recombination of coronaviruses. In F1, two cysteine protease-like domains and a growth factor-like one were revealed. One of the putative proteases of IBV is similar to 3C proteases of picornaviruses and related enzymes of como- nepo- and potyviruses. Search of IBV F1 and F2 sequences for sites similar to those cleaved by the latter proteases and intercomparison of the surrounding sequence stretches revealed 13 dipeptides Q/S(G) which are probably cleaved by the coronavirus 3C-like protease. Based on these observations, a partial tentative scheme for the functional organization and expression strategy of the non-structural polyproteins of IBV was proposed. It implies that, despite the general similarity to other positive strand RNA viruses, and particularly to potyviruses, coronaviruses possess a number of unique structural and functional features.

Amino Acid Sequence↗

PubMed1996

The herpes simplex virus type 2 strain HG52 RL1 gene contains a 154 bp intron as predicted from sequence analysis.

The published sequence of the herpes simplex virus (HSV) type 2 strain HG52 neurovirulence gene RL1 indicated that, unlike the HSV-1 homologue, the gene contains a 154 bp intron. This intron contains six complete and one partial copy of a 19 bp repeat which encodes a stop codon; thus all three forward frames are blocked. By RT-PCR of poly(A)+ RNA, using primers on either side of the proposed intron, we have isolated a partial cDNA clone corresponding to the predicted spliced mRNA.

Base Sequence↗

PubMed2003

Sequence analysis of segment a of a field virus isolate from an outbreak of Infectious bursal disease in India.

Sequence analysis of genome segment A of an Indian Infectious bursal disease virus (IBDV) field isolate (KT1/99) revealed total 95 nucleotide substitutions, resulting in 17 amino acid changes. Of these, five amino acid changes, namely F60S, T137I, I374V, V519I and E682D were unique to the KT1/99 isolate. The amino acid change P222A and the proposed hot mutation spot 680Y, reported to be present in very virulent IBDV isolates were also found in KT1/99. This isolate had nucleotide divergence of 1.1% to 4.95% from the other reported serotype 1 IBDV isolates and 19.6% from serotype 2 strain OH in polyprotein gene sequence, while divergence at amino acid level was 0.6% to 2.9% and 11.4%, respectively. Based on both nucleotide and amino acid sequence analysis, KT1/99 was grouped phylogenetically with the reported Bangladesh isolate BD3/99 in one cluster along with other reported very virulent isolates in same lineage.

Amino Acid Sequence↗

PubMed2003

Type-specific detection of human papillomaviruses in a routine laboratory setting--improved sensitivity and specificity of PCR and sequence analysis compared to direct hybridisation.

Human papillomaviruses (HPV) are known to cause cervical dysplasia and cervical carcinoma. We used a 3-step PCR protocol that allows rapid type-specific HPV testing in a routine laboratory setting: HPV-16-positive samples were determined using a specific LightCycler PCR; HPV-16-negative samples were amplified by nested PCR and typed by sequence analysis. During a period of 7 months, 1275 PCR-based HPV tests were performed. Of the 1275 samples, 829 samples tested negative for HPV and 446 tested positive, including 124 positives found in the initial HPV-16-specific LightCycler assay. Sequence analysis of 132 samples detected 18 HPV types that are not included in the widely used Hybrid Capture II assay. For comparison, the first 100 cervical specimens were tested in parallel using PCR and direct hybridisation (Hybrid Capture II assay). PCR detected HPV DNA in 23 samples that tested negative in the Hybrid Capture assay. Four out of 37 samples that tested positive for HPV in the Hybrid Capture test may be false positives, because sequence analysis detected HPV types not included in the probe mixtures. As rare and novel HPV types may also confer an oncogenic risk, highly sensitive and specific PCR assays will help in understanding cervical HPV infection and cervical cancer of unknown causes.

Adolescent↗

PubMed1991

[Polymerase chain reaction with subsequent direct gene sequence analysis. A possibility for molecular analysis in dermatology].

Molecular analyses are of increasing importance in clinical research as well as for diagnostic evaluations. Gene alterations are involved in the pathogenesis of numerous diseases and are described in an increasing number of conditions. A method is presented which allows for rapid and detailed nucleotide sequence analysis of a segment of a gene. Buccal epithelial cells of a patient are obtained by means of a mouth wash with 10 ml water. DNA molecules are amplified in vitro using the polymerase chain reaction, followed by direct sequence analysis of the product. Using this technique, a sequence analysis of a gene segment is possible within 1-2 days. As an example, the analysis of a segment of the gene for uroporphyrinogen decarboxylase of patients with cutanea tarda is described.

Base Sequence↗

PubMedDate not supplied

Sequence analysis of proteins.

There has been a rapid increase in the number of available protein sequences derived from gene-sequence information. Computer-based sequence analysis of proteins is gaining in importance as an analytical tool. With the help of these analyses such sequences may be characterized and some insights gained into their probable role in the system. The principles involved in computer-based sequence analysis and some of the methods are discussed.

Amino Acid Sequence↗

PubMed1990

Limited N-terminal sequence analysis.

Current methods in protein purification permit sequence analysis of picomole quantities of proteins and peptides. The key to obtaining sequence is to choose as the last step in the purification protocol the simplest (usually the fastest) method for isolating the protein or peptide.

Amino Acid Sequence↗

PubMed1990

Sequence analysis of proteins separated by polyacrylamide gel electrophoresis: towards an integrated protein database.

Improved technologies or the synergistic use of complementary methods enhance the efficiency of research and permit the exploration of new approaches for the investigation of complex problems. High sensitivity protein sequence analysis and polyacrylamide gel electrophoresis are such complementary methods. Here we summarize the current status of high sensitivity sequence analysis of proteins separated in polyacrylamide gels and discuss strategies by which this technology can enhance biological research by generating new approaches for the solution of complex, multifacetted problems. Finally, we outline imminent technological advances in the area of high sensitivity protein sequence analysis and argue that further technological developments will ultimately lead to the generation of an integrated protein database (containing structural and functional as well as physiological information in an easily accessible form) of all the proteins separated by high resolution two-dimensional gel electrophoresis.

Amino Acid Sequence↗

PubMed1998

Gene structure and sequence analysis of mouse centromere proteins A and C.

We have determined the genomic structure and organization of the mouse Cenpa and Cenpc genes. CENPA is a member of the histone H3-like proteins and is thought to replace histone H3 in centromeric nucleosomes. CENPC is a DNA-binding protein that is located at the inner kinetochore plate of active mammalian centromeres. The Cenpa cDNA encodes a 134-amino-acid product that is 70% identical and 84% similar to its human homolog. The mouse Cenpa gene is approximately 8 kb in length and contains five exons. Sequence analysis of the 5' DNA sequence of the gene revealed two consensus CAAT boxes, a putative TFIID-binding site, an Sp1-binding domain, and two cell cycle regulatory motifs, but no consensus TATA element. The mouse Cenpc gene spans 60 kb and contains 19 exons that range in size from 44 to 602 bp. Sequence analysis of the C+G-rich promoter region showed the presence of known promoter elements, including a CpG island, a CAAT box, and several GC boxes, but the absence of a consensus TATA element.

Amino Acid Sequence↗

PubMed1999

High-resolution sequence typing of HLA-DQA1 and -DQB1 exon 2 DNA with taxonomy-based sequence analysis (TBSA) allele assignment.

High-resolution DNA sequencing of exon 2 of DQA1 and DQB1 genes that uses a taxonomy-based sequence analysis (TBSA) method to assign alleles was developed. The system uses fewer primers for polymerase chain reaction (PCR) amplification and sequencing than other methods and yields accurate DQA1 and DQB1 typing when either homozygous or heterozygous DNA samples are tested. The approach was initially corroborated by the correct typing of 10 blinded samples that had been previously typed by PCR using sequence-specific oligonucleotide probes (PCR-SSOP) or serology, and subsequently confirmed by sequencing of cloned PCR products. DNA from peripheral blood cell samples of 130 individuals enrolled in a case-control analysis of HLA determinants of abdominal aortic aneurysm were subsequently evaluated. Overall, 8 different DQA1 and 19 DQB1 alleles were identified. All 21 DQA1 heterozygous combinations and 45 of 49 DQB1 heterozygous combinations were successfully resolved with TBSA. The two pairs of heterozygous DQB1 combinations that were not unambiguously typed required sequence specific PCR amplification for correct allele identification. We conclude that the method provides precise analysis for HLA-DQ typing.

DNA↗

PubMed1985

Usefulness of footprint-sequence analysis in lower-limb amputees.

Clinicians evaluated the usefulness of footprint-sequence analysis in 25 lower-limb amputees who were all prostheses wearers. The patients walked at a comfortable speed with their usual walking aids along a 2.24-m footprint-recording strip. Each patient's physical therapist and physician indicated on visual-analogue scales how useful they judged both raw and derived data to be in problem solving and as documentation for future comparison. Both groups of clinicians found this type of analysis moderately useful. We found no significant difference, but moderate correlation (r = .61, p less than .01), between their estimates of usefulness for problem solving and for future documentation. They considered the derived data slightly, but significantly, more useful than the raw data (t = 4.20, p less than .001). We found no significant difference or correlation between the estimates of physical therapists and those of physicians. The clinicians ranked pressure distribution, stride width, step length, foot angle, and stride length in order of perceived usefulness. Footprint-sequence analysis appears to be a moderately useful adjunct to the evaluation and documentation of the walking problems of lower-limb amputees. Both raw and derived data should be made available to the physical therapists and physicians caring for these patients.

Adolescent↗

PubMed2003

A Tudor protein with multiple SNc domains from pea seedlings: cellular localization, partial characterization, sequence analysis, and phylogenetic relationships.

A major high molecular weight protein (HMP) in the cytoskeletal fraction from pea has been purified. A combination of chromatographic techniques and protease fragment analysis also facilitated the isolation of the encoding cDNA, disclosing the sequence of the complete open reading frame. The protein possesses four complete N-terminal Staphylococcal nuclease (SNc) domains, a central Tudor domain and a partial SNc domain at the C-terminus, which may act as a coiled-coil cytoskeleton interaction motif. Cell fractionation studies showed that the protein was abundant in the cytoskeleton fraction in dark-grown pea seedlings, but essentially was absent from the nucleus. Gel filtration column chromatography indicated that the native protein exists as a dimer, while isoelectric focusing suggested that there were at least four HMP isotypes. The protein co-eluted with ribosomes from a heparin affinity column in vitro, consistent with ribosome/polysome interactions in vivo. Significantly, sequence analysis of the C-terminal SNc motif may accurately predict nuclear versus cytoplasmic localization resulting in potentially very different functional roles for this protein family in different organisms. An antibody to HMP from peas was also raised and an HMP with a similar molecular mass was detected in the cytoskeleton fractions and to a lesser extent in the nuclear fraction (250 g pellet) from rice and wheat seedlings.

Amino Acid Sequence↗

PubMed1991

Sequence analysis of DNA from formalin-fixed, paraffin-embedded human malignant melanoma.

Direct sequence analysis of in vitro amplified DNA from paraffin-embedded tissue is a promising new technique useful for detailed molecular analyses of material stored in dermatopathological archives. As only minute amounts of highly damaged DNA can be recovered from paraffin-embedded sections, sequence analysis of DNA from formalin-fixed and embedded tissue can result in less clear and readable data. We report here useful modifications that result in clear and readable sequence data. As an example, we detail the detection of a point mutation at codon 61 of the human N-ras gene in DNA from a formalin-fixed paraffin-embedded malignant melanoma specimen. This technique will be of value in many areas of molecular dermatopathology.

Base Sequence↗

PubMed1997

Sequence analysis by hybridization with oligonucleotide microchip: identification of beta-thalassemia mutations.

Diagnostics for genetic diseases were run and sequence analysis of DNA was carried out by hybridization of RNA transcripts with oligonucleotide array microchips. Polyacrylamide gel pads (100 x 100 x 20 microm) were fixed on a glass slide of the microchip and contained allele-specific immobilized oligonucleotides (10-mers). The RNA transcripts of PCR-amplified genomic DNA were fluorescently labeled by enzymatic or chemical methods and hybridized with the microchips. The simultaneous measurement in real time of the hybridization and melting on the entire oligonucleotide array was carried out with a fluorescence microscope equipped with CCD camera. The monitoring of the hybridization specificity for duplexes with different stabilities and AT content was enhanced by its measurement at optimal, discrimination temperatures on melting curves. Microchip diagnostics were optimized by choosing the proper allele-specific oligonucleotides from among the set of overlapping oligomers. The accuracy of mutation detection can be increased by simultaneous hybridization of the microchip with two differently labeled samples and by parallel monitoring their hybridization with a multi-wavelength fluorescence microscope. The efficiency and reliability of the sequence analysis were demonstrated with diagnostics for beta-thalassemia mutations.

Base Sequence↗

PubMed2003

Sequence analysis of EBV DNA isolated from mouth washings and PBMCs of healthy individuals and blood of EBV-LPD patients.

BACKGROUND: Lymphoproliferative disorder (LPD) caused by Epstein-Barr virus (EBV) is a severe complication of bone marrow transplantation. The EBV strain causing LPD is of either donor or recipient origin, however, available data are limited to only a small number of cases. To obtain solid evidence, comparison of the EBV strain that caused the EBV-LPD with pre-stem cell transplantation (SCT) EBV strains of donor and recipient is imperative. Available techniques rely on the production of EBV transformed lymphoblastoid cell lines and lack sensitivity. OBJECTIVE: The aim of this study was to develop a simple method for EBV sequence analysis on mouth washings (MWs) and peripheral blood mononuclear cells (PBMCs). STUDY DESIGN: EBV DNA was extracted from MWs and PBMCs that were collected from 20 healthy individuals. DNA was used for sequence analysis, using a polymerase chain reaction for the C-terminus of the LMP-1 gene. RESULTS: In seropositive individuals EBV DNA could be detected in 11/14 (79%) MWs and in 13/14 (93%) PBMC samples. Sequence analysis showed that in 11 out of 14 (79%) healthy individuals sequence patterns could be established. In these 11 healthy individuals 13 sequence patterns could be detected. Eleven of these 13 patterns (84.6%) were unique. These results encouraged us to explore the feasibility of this method on EBV DNA isolated from plasma from 9 EBV-LPD patients at time of EBV reactivation. In 7 EBV-LPD patients 8 sequence patterns were detected. Six out of 8 sequence patterns (75%) were unique. CONCLUSION: Our method is suitable for strain identification and we intend to use this technique to evaluate EBV origin in EBV-LPD patients.

Adult↗

PubMed1994

RNA sequence analysis using covariance models.

We describe a general approach to several RNA sequence analysis problems using probabilistic models that flexibly describe the secondary structure and primary sequence consensus of an RNA sequence family. We call these models 'covariance models'. A covariance model of tRNA sequences is an extremely sensitive and discriminative tool for searching for additional tRNAs and tRNA-related sequences in sequence databases. A model can be built automatically from an existing sequence alignment. We also describe an algorithm for learning a model and hence a consensus secondary structure from initially unaligned example sequences and no prior structural information. Models trained on unaligned tRNA examples correctly predict tRNA secondary structure and produce high-quality multiple alignments. The approach may be applied to any family of small RNA sequences.

Algorithms↗

PubMed1993

Doing sequence analysis with your printer.

The software package RSVP (Rapid Sequence Visualization in PostScript) has a suite of visually oriented sequence analysis routines implemented entirely in the page description language PostScript, a widely used standard that is built into many printers. RSVP is thus a relatively platform-independent tool for providing a 'quick look' at sequence data, using form and color to help point out patterns, in advance of more sophisticated sequence analyses.

Amino Acid Sequence↗