Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “bioinformatic database”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 919 records · Page 51Linked to original sources
PubMed1998

IMGT/LIGM-DB: a systematized approach for ImMunoGeneTics database coherence and data distribution improvement.

IMGT, the international ImMunoGeneTics database (http:(/)/imgt.cnusc.fr:8104), created by Marie-Paule Lefranc, Montpellier, France, is an integrated database specializing in antigen receptors and MHC of all vertebrate species. IMGT includes LIGM-DB, developed for Immunoglobulins and T-cell-receptors. LIGM-DB distributes high quality data with an important increment value added by the LIGM expert annotations. LIGM-DB accurate immunogenetics data is based on the standardization of biological knowledge related to keywords, annotation labels and gene identification. The management of such data resulting from biological research requires an high flexible implementation to quickly reflect up-to-date results, and to integrate new knowledge. We developed a systematized approach and defined LIGM-DB systems which manage and realize the major tasks for the database survey. In this paper, we will focus on the coherence system, which became absolutely crucial to maintain data quality as the database is growing up and as the biological knowledge continues to improve, and on the distribution system which makes LIGM-DB data easy to access, download and reuse. Efforts have been done to improve the data distribution procedures and adapt them to the current bioinformatics needs. Recently, we have developed an API which allows Java programmers to remotely access and integrate LIGM-DB data in other computer environments.

Animals↗
PubMed2005

Pathogenomics analysis of Leishmania spp.: flagellar gene families of putative virulence factors.

The trypanosomatid flagellar apparatus contains conventional and unique features, whose roles in infectivity are still enigmatic. Although the flagellum and the flagellar pocket are critical organelles responsible for all vesicular trafficking between the cytoplasm and cell surface, still very little is known about their roles in pathogenesis and how molecules get to and from the flagellar pocket. The ongoing analysis of the genome sequences and proteome profiles of Leishmania major and L infantum, Trypanosoma cruzi, T. brucei, and T. gambiensi ( www.genedb.org ), coupled with our own work on L. chagasi (as part of the Brazilian Northeast Genome Program- www.progene.ufpe.br ), prompted us to scrutinize flagellar genes and proteins of Leishmania spp. promastigotes that could be virulence factors in leishmaniasis. We have identified some overlooked parasite factors such as the MNUDC-1 (a protein involved in nuclear development and genomic fusion) and SQS (an enzyme of sterol biosynthesis), among the described flagellar gene families. A database concerning the results of this work, as well as of other studies of Leishmania and its organelles, is available at http://nugen.lcc.uece.br/LPGate . It will serve as a convenient bioinformatics resource on genomics and pathology of the etiological agents of leishmaniasis.

Amino Acid Sequence↗
PubMed2004

Development of a mass fingerprinting tool for automated interpretation of oligosaccharide fragmentation data.

The bioinformatic tool GlycosidIQ was developed for computerized interpretation of oligosaccharide mass spectrometric fragmentation based on matching experimental data with theoretically fragmented oligosaccharides generated from the database GlycoSuiteDB. This use of the software for glycofragment mass fingerprinting obviates a large part of the manual, labor intensive, and technically challenging interpretation of oligosaccharide fragmentation. Using 130 negative ion electrospray ionization-tandem mass spectrometry fragment spectra from identified oligosaccharide structures, it was shown that the GlycosidIQ scoring algorithms were able to correctly identify oligosaccharides in the great majority of cases (correct structure top ranked in 78% of the cases and an additional 17% were ranked second highest in the sample set).

Algorithms↗
PubMed2002

The SH3 domain of nebulin binds selectively to type II peptides: theoretical prediction and experimental validation.

Nebulin, a giant modular protein from muscle, is thought to act as a molecular ruler in sarcomere assembly. The C terminus of nebulin, located in the sarcomere Z-disk, comprises an SH3 domain, a module well known for its role in protein/protein interactions. SH3 domains are known to recognize proline-rich ligands, which have been classified as type I or type II, depending on their relative orientation with respect to the SH3 domain in the complex formed. Type I ligands are bound with their N terminus at the RT loop of the SH3 domain, while type II ligands are bound with their C terminus at the RT loop. Many SH3 domains can bind peptides of either class. Despite the potential importance of the SH3 domain for the function of nebulin as an integral part of a complex network of interactions, no in vivo partner has been identified so far. We have adopted an integrated approach, which combines bioinformatic tools with experimental validation to identify possible partners of nebulin SH3. Using the program SPOT, we performed an exhaustive screening of the muscle sequence databases. This search identified a number of potential nebulin SH3 partners, which were then tested experimentally for their binding affinity. Synthetic peptides were studied by both fluorescence and NMR spectroscopy. Our results show that nebulin SH3 domain binds selectively to type II peptides. The affinity for a type II peptide, 12 residues long, spanning the sequence of a stretch of titin known to colocalise with nebulin in the Z-disk is in the submicromolar range (0.7 microM). This affinity is among the highest found for SH3/peptide complexes, suggesting that the identified stretch could have significance in vivo. The strategy outlined here is of more general applicability and may provide a valuable tool to identify potential partners of SH3 domains and of other peptide-binding modules.

Amino Acid Sequence↗
PubMed2003

ESTAnnotator: A tool for high throughput EST annotation.

In high throughput sequence analysis, it is often necessary to combine the results of contemporary bioinformatics tools, because no individual tool alone computes all the requested information. ESTAnnotator is a tool for the high throughput annotation of expressed sequence tags (ESTs) by automatically running a collection of bioinformatics applications. In the first step, a quality check is performed and repeats, vector parts and low quality sequences are masked. Then successive steps of database searching and EST clustering are performed. Already known transcripts present within mRNA and genomic DNA reference databases are identified. Subsequently, tools for the clustering of anonymous ESTs, and for further database searches at the protein level, are applied. Finally, the outputs of each individual tool are gathered and the relevant results presented in a descriptive summary. ESTAnnotator was already successfully applied for the systematic identification and characterisation of novel human genes involved in cartilage/bone formation, growth, differentiation and homeostasis. ESTAnnotator is available at http://genome.dkfz-heidelberg.de, contact: genome@dkfz.de.

Cartilage↗
PubMed2005

The peptidomics concept.

Peptides are a paramount example of how nature diversifies from one single gene to release multiple, regulated functionalities at the desired sites and time. To achieve this, peptides are sequentially generated by a complex network of more than 500 proteases, acting at intracellular sites, upon secretion, in extracellular environments, and, finally, serving (regulated) degradation. This cycle of maturation, activation, and degradation points out that the peptidome is mechanistically linked to the proteome: the distribution between both is regulated by proteases and counter-regulated by protease inhibitors. Given the high diversity of peptides in living systems and their involvement in key regulatory processes, a need for improved peptide discovery, ideally combining peptide sequence identification with peptide profiling, has emerged. Standard proteomic approaches are not suitable for a systematic peptide analysis, since they do not cover the low molecular mass window. The new direction in proteomic research to analyse this "terra incognita" is peptidomics. This novel concept aims at the comprehensive visualization and analysis of small polypeptides, thus covering the mass range between proteomics and metabonomics. The pacemakers for the development of peptidomics technologies are modern mass spectrometry and bioinformatics. They are ideally suited for sensitive and comprehensive peptide analysis, especially in combination with the massive information content of today's genomic and transcriptomic databases. Given the high diversity of native peptides in living systems, clinical chemistry and modern medicine are the prime application areas. The discovery of relevant peptide biomarkers and drug targets will strongly benefit from peptidomics.

Animals↗
PubMed2003

Profile-profile alignment: a powerful tool for protein structure prediction.

The problem of computing the tertiary structure of a protein from a given amino acid sequence has been a major subject of bioinformatics research during the last decade. Many different approaches have been taken to tackle the problem, the most successful of which are based on searching databases to identify a similar amino acid sequence in the PDB and using the corresponding structure as a template for modeling the structure of the query sequence. An important advance for the evaluation of sequence similarity in this context has been the use of a frequency profile that represents a part of the protein sequence space close to the query sequence instead of the query sequence itself. In this paper, we present a further extension of this principle by using profiles instead of the template sequences, also. We show that, by using our newly developed scoring model, the profile-profile alignment approach is able to significantly outperform current state of the art methods like PSI-BLAST, HMMs, or threading methods in a fold recognition setup. This is especially interesting since we show that it holds for closely related sequences as well as for very distantly related ones.

Algorithms↗
PubMed2026

Interleukin-23 Receptor and Interleukin-17 Receptor A: Splice Variants, Isoforms and Their Relationship With Periodontitis-A Systematic Review and Bioinformatic Analysis.

This systematic review aimed to: (1) identify the splicing variants of IL23R and IL17RA reported in the literature; (2) perform a multiple alignment analysis to describe the isoforms of IL-23R and IL-17RA; and (3) compare the expression levels of IL-23R, IL-17RA, and their soluble isoforms (sIL-23R and sIL-17RA) in patients with periodontitis and periodontally healthy individuals. The study protocol followed PRISMA guidelines and was registered in PROSPERO (CRD420251267367). Six databases (PubMed, ScienceDirect, Scopus, Web of Science, EBSCO, and Google Scholar) were searched without restrictions on year or language. The descriptors used were: 'Interleukin-23 Receptor,' 'IL-23R,' 'Interleukin-17 Receptor A' 'IL-17RA,' 'Alternative Splicing,' 'Splice Variants,' 'Isoforms,' and 'Periodontitis.' The bioinformatics analysis was performed using CLUSTALW (V.1.83), InterPro and DeepTMHMM. Risk of bias was assessed with the QUIN and JBI tools for cross-sectional studies. Of 104 articles, four in vitro studies and eight cross-sectional studies were included. Qualitative analysis revealed that to date there are 32 splicing variants of the IL23R gene, while only one splicing variant has been reported for IL17RA. CLUSTALW, InterPro and DeepTMHMM analysis showed that these splicing variants result in 23 isoforms which can be soluble forms, complete intracellular peptides, truncated extracellular or intracellular peptides, or complete structures with truncated extracellular and/or intracellular domains. All studies had a low risk of bias. IL-23R and IL-17RA exhibit structural diversity resulting from alternative splicing, with IL-23R demonstrating significantly greater isoform complexity. However, the biological significance of these isoforms in periodontitis remains unclear and requires further investigation.

Humans↗
PubMed2005

A relative-entropy algorithm for genomic fingerprinting captures host-phage similarities.

The degeneracy of codons allows a multitude of possible sequences to code for the same protein. Hidden within the particular choice of sequence for each organism are over 100 previously undiscovered biologically significant, short oligonucleotides (length, 2 to 7 nucleotides). We present an information-theoretic algorithm that finds these novel signals. Applying this algorithm to the 209 sequenced bacterial genomes in the NCBI database, we determine a set of oligonucleotides for each bacterium which uniquely characterizes the organism. Some of these signals have known biological functions, like restriction enzyme binding sites, but most are new. An accompanying scoring algorithm is introduced that accurately (92%) places sequences of 100 kb with their correct species among the choice of hundreds. This algorithm also does far better than previous methods at relating phage genomes to their bacterial hosts, suggesting that the lists of oligonucleotides are "genomic fingerprints" that encode information about the effects of the cellular environment on DNA sequence. Our approach provides a novel basis for phylogeny and is potentially ideally suited for classifying the short DNA fragments obtained by environmental shotgun sequencing. The methods developed here can be readily extended to other problems in bioinformatics.

Algorithms↗
PubMed2004

Statistical evaluation of local alignment features predicting allergenicity using supervised classification algorithms.

BACKGROUND: Recently, two promising alignment-based features predicting food allergenicity using the k nearest neighbor (kNN) classifier were reported. These features are the alignment score and alignment length of the best local alignment obtained in a database of known allergen sequences. METHODS: In the work reported here a much more comprehensive statistical evaluation of the potential of these features was performed, this time for the prediction of allergenicity in general. The evaluation consisted of the following four key components. (1) A new high quality database consisting of 318 carefully selected, non-redundant allergens and 1,007 sequences carefully selected to be non-allergens. (2) Three different supervised algorithms: the kNN classifier, the Bayesian linear Gaussian classifier, and the Bayesian quadratic Gaussian classifier. (3) A large set of local alignment procedures defined using the FASTA3 alignment program by means of a wide range of different parameter settings. (4) Novel performance curves, alternative to conventional receiver-operating characteristic curves, to display not only average behaviors but also statistical variations due to small data sets. RESULTS: The linear Gaussian classifier proved most useful among the tested supervised machine learning algorithms, closely followed by the quadratic Gaussian equivalent and kNN. The overall best classification results were obtained with a novel feature vector consisting of the combined alignment scores derived from local alignment procedures using different substitution matrices. CONCLUSIONS: The models reported here should be useful as a part of an integrated assessment scheme for potential protein allergenicity and for future comparisons with alternative bioinformatic approaches.

Algorithms↗
PubMed2005

Prediction of protease types in a hybridization space.

Regulating most physiological processes by controlling the activation, synthesis, and turnover of proteins, proteases play pivotal regulatory roles in conception, birth, digestion, growth, maturation, ageing, and death of all organisms. Different types of proteases have different functions and biological processes. Therefore, it is important for both basic research and drug discovery to consider the following two problems. (1) Given the sequence of a protein, can we identify whether it is a protease or non-protease? (2) If it is, what protease type does it belong to? Although the two problems can be solved by various experimental means, it is both time-consuming and costly to do so. The avalanche of protein sequences generated in the post-genetic era has challenged us to develop an automated method for making a fast and reliable identification. By hybridizing the functional domain composition and pseudo-amino acid composition, we have introduced a new method called "FunD-PseAA predictor" that is operated in a hybridization space. To avoid redundancy and bias, demonstrations were performed on a dataset where none of the proteins has >or=25% sequence identity to any other. The overall success rate thus obtained by the jackknife cross-validation test in identifying protease and non-protease was 92.95%, and that in identifying the protease type was 94.75% among the following six types: (1) aspartic, (2) cysteine, (3) glutamic, (4) metallo, (5) serine, and (6) threonine. Demonstration was also made on an independent dataset, and the corresponding overall success rates were 98.36% and 97.11%, respectively, suggesting the FunD-PseAA predictor is very powerful and may become a useful tool in bioinformatics and proteomics.

Algorithms↗
PubMed2004

Jemboss reloaded.

Bioinformatics tools are freely available from websites all over the world. Often they are presented as web services, although there are many tools for download and use on a local machine. This tutorial section looks at Jemboss, a Java-based graphical user interface (GUI) for the EMBOSS bioinformatics suite, which combines the advantages of both web service and downloaded software.

Computational Biology↗
PubMed2005

The role of informatics in the coordinated management of biological resources collections.

The term 'biological resources' is applied to the living biological material collected, held and catalogued in culture collections: bacterial and fungal cultures; animal, human and plant cells; viruses; and isolated genetic material. A wealth of information on these materials has been accumulated in culture collections, and most of this information is accessible. Digitalisation of data has reached a high level; however, information is still dispersed. Individual and coordinated approaches have been initiated to improve accessibility of biological resource centres, their holdings and related information through the Internet. These approaches cover subjects such as standardisation of data handling and data accessibility, and standardisation and quality control of laboratory procedures. This article reviews some of the most important initiatives implemented so far, as well as the most recent achievements. It also discusses the possible improvements that could be achieved by adopting new communication standards and technologies, such as web services, in view of a deeper and more fruitful integration of biological resources information in the bioinformatics network environment.

Animals↗
PubMed2004

Identification and characterization of a novel RNA binding protein that associates with the 5'-untranslated region of the chloroplast psbA mRNA.

Binding of proteins to chloroplast-encoded mRNAs has been shown to be an essential part of chloroplast gene expression. Four nuclear-encoded proteins (38, 47, 55, and 60 kDa) have been identified that bind to the 5'-untranslated region of the Chlamydomonas reinhardtii psbA mRNA with high affinity and specificity. We have cloned a cDNA that represents the 38 kDa protein (RB38) and show that it encodes a novel RNA binding protein that is primarily localized within the chloroplast stroma. RB38 contains four 70 amino acid repeats with a high percentage of basic amino acids, as well as an amino-terminal extension predicted to act as a chloroplast import sequence. We demonstrate that the 38 kDa precursor protein is imported into isolated chloroplasts and interacts with high specificity to uridine-rich regions within the 5'-untranslated region of the psbA mRNA. While database searches have identified hypothetical proteins from several other eukaryotic species with high sequence similarity to the deduced amino acid sequence of RB38, no proteins with homology to RB38 have been biochemically characterized. Bioinformatic analysis of the RB38 sequence, together with structure analysis using circular dichroism and protein modeling, suggests that the 70 amino acid repeats within RB38 are similar in fold to previously identified RNA binding motifs, despite limited sequence homology.

5' Untranslated Regions↗
PubMed2003

Bioinformatic strategies for better understanding of immune function.

Novartis Foundation sponsored a Symposium which brought together a group of experimental immunologists, theoretical immunologists, and bioinformaticians to discuss the new field of immunoinformatics. The discussion focused on immunological databases, antigen processing and presentation, immunogenomics, host-pathogen interactions, and mathematical modelling of the immune system. A main conclusion of the meeting is the critical role played by immunoinformatics in current immunology research. In particular, immunoinformatics provides a foundation for the emerging fields of systems immunology and immunogenomics.

Allergy and Immunology↗
PubMed2005

PARALIGN: rapid and sensitive sequence similarity searches powered by parallel computing technology.

PARALIGN is a rapid and sensitive similarity search tool for the identification of distantly related sequences in both nucleotide and amino acid sequence databases. Two algorithms are implemented, accelerated Smith-Waterman and ParAlign. The ParAlign algorithm is similar to Smith-Waterman in sensitivity, while as quick as BLAST for protein searches. A form of parallel computing technology known as multimedia technology that is available in modern processors, but rarely used by other bioinformatics software, has been exploited to achieve the high speed. The software is also designed to run efficiently on computer clusters using the message-passing interface standard. A public search service powered by a large computer cluster has been set-up and is freely available at www.paralign.org, where the major public databases can be searched. The software can also be downloaded free of charge for academic use.

Algorithms↗
PubMed2004

Gene expression analysis in the hippocampal formation of tree shrews chronically treated with cortisol.

Adrenal corticosteroids influence the function of the hippocampus, the brain structure in which the highest expression of glucocorticoid receptors is found. Chronic high levels of cortisol elicited by stress or through exogenous administration can cause irreversible damage and cognitive deficits. In this study, we searched for genes expressed in the hippocampal formation after chronic cortisol treatment in male tree shrews. Animals were treated orally with cortisol for 28 days. At the end of the experiments, we generated two subtractive hippocampal hybridization libraries from which we sequenced 2,246 expressed sequenced tags (ESTs) potentially regulated by cortisol. To validate this approach further, we selected some of the candidate clones to measure mRNA expression levels in hippocampus using real-time PCR. We found that 66% of the sequences tested (10 of 15) were differentially represented between cortisol-treated and control animals. The complete set of clones was subjected to a bioinformatic analysis, which allowed classification of the ESTs into four different main categories: 1) known proteins or genes (approximately 28%), 2) ESTs previously published in the database (approximately 16%), 3) novel ESTs matching only the reference human or mouse genome (approximately 5%), and 4) sequences that do not match any public database (50%). Interestingly, the last category was the most abundant. Hybridization assays revealed that several of these clones are indeed expressed in hippocampal tissue from tree shrew, human, and/or rat. Therefore, we discovered an extensive inventory of new molecular targets in the hippocampus that serves as a reference for hippocampal transcriptional responses under various conditions. Finally, a detailed analysis of the genomic localization in human and mouse genomes revealed a survey of putative novel splicing variants for several genes of the nervous system.

Animals↗