RNA secondary structure prediction by centroids in a Boltzmann weighted ensemble

Prediction of RNA secondary structure by free energy minimization has been the standard for over two decades. Here we describe a novel method that forsakes this paradigm for predictions based on Boltzmann-weighted structure ensemble. We introduce the notion of a centroid structure as a representative for a set of structures and describe a procedure for its identification. In comparison with the minimum free energy (MFE) structure using diverse types of structural RNAs, the centroid of the ensemble makes 30.0% fewer prediction errors as measured by the positive predictive value (PPV) with marginally improved sensitivity. The Boltzmann ensemble can be separated into a small number (3.2 on average) of clusters. Among the centroids of these clusters, the "best cluster centroid" as determined by comparison to the known structure simultaneously improves PPV by 46.5% and sensitivity by 21.7%. For 58% of the studied sequences for which the MFE structure is outside the cluster containing the best centroid, the improvements by the best centroid are 62.5% for PPV and 31.4% for sensitivity. These results suggest that the energy well containing the MFE structure under the current incomplete energy model is often different from the one for the unavailable complete model that presumably contains the unique native structure. Centroids are available on the Sfold server at http://sfold.wadsworth.org.     

WWW access to the SYSTERS protein sequence cluster set

SUMMARY: We present a Web server where the SYSTERS cluster set of the non-redundant protein database consisting of sequences from SWISS-PROT and PIR is being made available for querying and browsing. The cluster set can be searched with a new sequence using the SSMAL search tool. Additionally, a multiple alignment is generated for each cluster and annotated with domain information from the Pfam protein family database. AVAILABILITY: The server address is http://www.dkfz-heidelberg.de/tbi/services/cluster/ systersform     

Habitat preferences of Red-backed Shrikes Lanius collurio and Barred Warblers Sylvia nisoria breeding sympatrically in a wetland/farmland mosaic

Capsule: The Red-backed Shrike Lanius collurio and the Barred Warbler Sylvia nisoria had similar habitat preferences and their territories often overlapped. However, we found that Red-backed Shrikes were more flexible in habitat choice whilst Barred Warblers had more specific requirements.

Aim: We aimed to analyse and compare distribution and habitat preferences of Red-backed Shrikes and Barred Warblers breeding sympatrically in semi-natural landscape in a wetland/farmland mosaic.

Methods: We examined habitat availability and use by the two species within their breeding territories to identify differences in habitat selection.

Results: Territories of both species were similar in habitat composition and used levees, bushes, fallow areas and single trees. However, the spatial characteristics of the territories differed between species. Red-backed Shrikes used a wider range of sizes and shapes of habitat patches, whilst Barred Warblers preferred a more complex landscape structure and a higher diversity of habitat types. We also found that areas of 71% of Barred Warbler and 34% of Red-backed Shrike territories overlapped.

Conclusion: Whilst both species showed similar habitat choices, they appeared to differ significantly in terms of landscape structure: Red-backed Shrikes were more flexible and less selective than Barred Warblers in their habitat choice.     

The design of Jemboss: a graphical user interface to EMBOSS

DESIGN: Jemboss is a graphical user interface (GUI) for the European Molecular Biology Open Software Suite (EMBOSS). It is being developed at the MRC UK HGMP-RC as part of the EMBOSS project. This paper explains the technical aspects of the Jemboss client-server design. The client-server model optionally allows that a Jemboss user have an account on the remote server. The Jemboss client is written in Java and is downloaded automatically to a user's workstation via Java Web Start using the HTML protocol. The client then communicates with the remote server using SOAP (Simple Object Access Protocol). A Tomcat server listens on the remote machine and communicates the SOAP requests to a Jemboss server, again written in Java. This Java server interprets the client requests and executes them through Java Native Interface (JNI) code written in the C language. Another C program having setuid privilege, jembossctl, is called by the JNI code to perform the client requests under the user's account on the server. The commands include execution of EMBOSS applications, file management and project management tasks. Jemboss allows the use of JSSE for encryption of communication between the client and server. The GUI parses the EMBOSS Ajax Command Definition language for form generation and maximum input flexibility. Jemboss interacts directly with the EMBOSS libraries to allow dynamic generation of application default settings. RESULTS: This interface is part of the EMBOSS distribution and has attracted much interest. It has been set up at many other sites globally as well as being used at the HGMP-RC for registered users. AVAILABILITY: The software, EMBOSS and Jemboss, is freely available to academics and commercial users under the GPL licence. It can be downloaded from the EMBOSS ftp server: http://www.uk.embnet.org/Software/EMBOSS/, ftp://ftp.uk.embnet.org/pub/EMBOSS/. Registered HGMP-RC users can access an installed server from: http://www.uk.embnet.org/Software/EMBOSS/Jemboss/     

GeneSeqer@PlantGDB: Gene structure prediction in plant genomes

The GeneSeqer@PlantGDB Web server (http://www.plantgdb.org/cgi-bin/GeneSeqer.cgi) provides a gene structure prediction tool tailored for applications to plant genomic sequences. Predictions are based on spliced alignment with source-native ESTs and full-length cDNAs or non-native probes derived from putative homologous genes. The tool is illustrated with applications to refinement of current gene structure annotation and de novo annotation of draft genomic sequences. The service should facilitate expert annotation as a community effort by providing convenient access to all public plant sequences via the PlantGDB database, a simple four-step protocol for spliced alignment and visually appealing displays of the predicted gene structures in addition to detailed sequence alignments.     

ModLoop: automated modeling of loops in protein structures

SUMMARY: ModLoop is a web server for automated modeling of loops in protein structures. The input is the atomic coordinates of the protein structure in the Protein Data Bank format, and the specification of the starting and ending residues of one or more segments to be modeled, containing no more than 20 residues in total. The output is the coordinates of the non-hydrogen atoms in the modeled segments. A user provides the input to the server via a simple web interface, and receives the output by e-mail. The server relies on the loop modeling routine in MODELLER that predicts the loop conformations by satisfaction of spatial restraints, without relying on a database of known protein structures. For a rapid response, ModLoop runs on a cluster of Linux PC computers. AVAILABILITY: The server is freely accessible to academic users at http://salilab.org/modloop     

Advances in proteomic study of cardiac amyloidosis: progress and potential

Introduction: More than ten distinct forms of amyloidoses that can involve the heart have been described, classified according to which protein originates the deposits. Cardiac amyloid infiltration translates into progressive and often life-threatening cardiomyopathy, but disease severity, prognosis and treatment drastically differ according to the amyloidosis type. The notion that protein misfolding and aggregation play a more general role in human cardiomyopathies has further raised attention towards the definition of the proteotoxicity mechanisms.

Areas covered: Mass spectrometry-based proteomics plays an important role as a diagnostic tool and for understanding the molecular bases of amyloid cardiomyopathies. The landscape of applications of proteomics to the study of cardiac amyloidoses and amyloid-related cardiotoxicity is summarized, with a critical synthesis of the major achievements.

Expert commentary: Current strengths and limitations of proteomics in the clinical setting and in translational research on amyloid cardiomyopathy are discussed, with the foreseen potential future directions in the field.     

Cancer biomarker discovery and translation: proteomics and beyond

Introduction: Cancer is often diagnosed at late stages when the chance of cure is relatively low and although research initiatives in oncology discover many potential cancer biomarkers, few transition to clinical applications. This review addresses the current landscape of cancer biomarker discovery and translation with a focus on proteomics and beyond.

Areas covered: The review examines proteomic and genomic techniques for cancer biomarker detection and outlines advantages and challenges of integrating multiple omics approaches to achieve optimal sensitivity and address tumor heterogeneity. This discussion is based on a systematic literature review and direct participation in translational studies.

Expert commentary: Identifying aggressive cancers early on requires improved sensitivity and implementation of biomarkers representative of tumor heterogeneity. During the last decade of genomic and proteomic research, significant advancements have been made in next generation sequencing and mass spectrometry techniques. This in turn has led to a dramatic increase in identification of potential genomic and proteomic cancer biomarkers. However, limited successes have been shown with translation of these discoveries into clinical practice. We believe that the integration of these omics approaches is the most promising molecular tool for comprehensive cancer evaluation, early detection and transition to Precision Medicine in oncology.     

Forests for Energy and the Role of Planted Trees

Woodfuels currently supply 7 percent of worldwide energy use and are much more important in developing than developed countries. Worldwide fuelwood use may be slowly declining, while charcoal production is increasing. In developing countries, woodfuel comes from natural forests, woodlands, shrublands, plantations and trees outside forests; the last is often the most important source. In developed countries, woodfuels are largely from industrial roundwood processing where up to 50 percent of logs may be used for energy. In urban areas, of both developing and developed countries, woodfuels also arises from wood processing and construction and other urban residues including tree trimming. Currently, apart from some nonindustrial plantations and the small areas of energy plantations, woodfuel largely results from by-products and residues.

Forest plantation may currently provide 15 to 20 percent of all fuelwood and this contribution will rise due to continued tree planting plus the rapidly increasing industrial plantation harvest. However, forest and woodfuel-use data are of uneven quality, making estimates tenuous.

There is potential to increase the amount of woodfuels in developed countries but its use will depend on fossil fuel price increases, and on ecological and social issues. In Nordic countries, forest residue use has grown, being underpinned by carbon taxes and research and development. Site nutrient conservation is assisted by leaving foliage on site and by returning the ash after burning. Leaving bark on site may be important for eucalypts.

In developing countries participatory programmes are critical for encouraging tree planting. Farmers seldom plant for fuelwood alone. Large-scale fuelwood plantations programs have not always been successful. Agroforestry practices are often practiced as they provide multiple benefits, including the provision of woodfuel. Silviculture should be readily adoptable, with special attention being given to species selection, high-quality planting stock, establishment methods and protection from animals.

Because of woodfuel's low relative value, energy is seldom a management objective of industrial plantations. However, often silviculture could be altered to increase bioenergy output, particularly with those sawlog regimes based on low stockings and non-extraction thinnings, and through more intensive silviculture. As a supplement to current silvicultural decision-making tools, energy analysis of silvicultural options would assist in efficient allocation of fossil fuels.     

OLDERADO: on-line database of ensemble representatives and domains. On Line Database of Ensemble Representatives And DOmains.

In cases where the structure of a single protein is represented by an ensemble of conformations, there is often a need to determine the common features and to choose a "representative" conformation. This occurs, for example, with structures determined by NMR spectroscopy, analysis of the trajectory from a molecular dynamics simulation, or an ensemble of structures produced by comparative modeling. We reported previously automatic methods for (1) defining the atoms with low spatial variance across an ensemble (i.e., the "core" atoms) and the domains in which these atoms lie, and (2) clustering an ensemble into conformationally related subfamilies. To extend the utility of these methods, we have developed a freely available server on the World Wide Web at http:/(/)neon.chem.le.ac.uk/olderado/. This (1) contains an automatically generated database of representative structures, core atoms, and domains determined for 449 ensembles of NMR-derived protein structures in the Protein Data Bank (PDB) in May 1997, and (2) allows the user to upload a PDB-formatted file containing the coordinates of an ensemble of structures. The server returns in real time: (1) information on the residues constituting domains: (2) the structures that constitute each conformational subfamily; and (3) an interactive java-based three-dimensional viewer to visualise the domains and clusters. Such information is useful, for example, when selecting conformations to be used in comparative modeling and when choosing parts of structures to be used in molecular replacement. Here we describe the OLDERADO server.     

ProServer: a simple, extensible Perl DAS server

SUMMARY: The increasing size and complexity of biological databases has led to a growing trend to federate rather than duplicate them. In order to share data between federated databases, protocols for the exchange mechanism must be developed. One such data exchange protocol that is widely used is the Distributed Annotation System (DAS). For example, DAS has enabled small experimental groups to integrate their data into the Ensembl genome browser. We have developed ProServer, a simple, lightweight, Perl-based DAS server that does not depend on a separate HTTP server. The ProServer package is easily extensible, allowing data to be served from almost any underlying data model. Recent additions to the DAS protocol have enabled both structure and alignment (sequence and structural) data to be exchanged. ProServer allows both of these data types to be served. AVAILABILITY: ProServer can be downloaded from http://www.sanger.ac.uk/proserver/ or CPAN http://search.cpan.org/~rpettett/. Details on the system requirements and installation of ProServer can be found at http://www.sanger.ac.uk/proserver/.     

Gene structure prediction from consensus spliced alignment of multiple ESTs matching the same genomic locus

MOTIVATION: Accurate gene structure annotation is a challenging computational problem in genomics. The best results are achieved with spliced alignment of full-length cDNAs or multiple expressed sequence tags (ESTs) with sufficient overlap to cover the entire gene. For most species, cDNA and EST collections are far from comprehensive. We sought to overcome this bottleneck by exploring the possibility of using combined EST resources from fairly diverged species that still share a common gene space. Previous spliced alignment tools were found inadequate for this task because they rely on very high sequence similarity between the ESTs and the genomic DNA. RESULTS: We have developed a computer program, GeneSeqer, which is capable of aligning thousands of ESTs with a long genomic sequence in a reasonable amount of time. The algorithm is uniquely designed to tolerate a high percentage of mismatches and insertions or deletions in the EST relative to the genomic template. This feature allows use of non-cognate ESTs for gene structure prediction, including ESTs derived from duplicated genes and homologous genes from related species. The increased gene prediction sensitivity results in part from novel splice site prediction models that are also available as a stand-alone splice site prediction tool. We assessed GeneSeqer performance relative to a standard Arabidopsis thaliana gene set and demonstrate its utility for plant genome annotation. In particular, we propose that this method provides a timely tool for the annotation of the rice genome, using abundant ESTs from other cereals and plants. AVAILABILITY: The source code is available for download at http://bioinformatics.iastate.edu/bioinformatics2go/gs/download.html. Web servers for Arabidopsis and other plant species are accessible at http://www.plantgdb.org/cgi-bin/AtGeneSeqer.cgi and http://www.plantgdb.org/cgi-bin/GeneSeqer.cgi, respectively. For non-plant species, use http://bioinformatics.iastate.edu/cgi-bin/gs.cgi. The splice site prediction tool (SplicePredictor) is distributed with the GeneSeqer code. A SplicePredictor web server is available at http://bioinformatics.iastate.edu/cgi-bin/sp.cgi     

MPSA: integrated system for multiple protein sequence analysis with client/server capabilities

SUMMARY: MPSA is a stand-alone software intended to protein sequence analysis with a high integration level and Web clients/server capabilities. It provides many methods and tools, which are integrated into an interactive graphical user interface. It is available for most Unix/Linux and non-Unix systems. MPSA is able to connect to a Web server (e.g. http://pbil.ibcp.fr/NPSA) in order to perform large-scale sequence comparison on up-to-date databanks. AVAILABILITY: Free to academic http://www.ibcp.fr/mpsa/ CONTACT: c.blanchet@ibcp.fr     

The role of mass spectrometry in the characterization of biologic protein products

Introduction: Mass spectrometry (MS) is widely used in the characterization of biomolecules including peptide and protein therapeutics. These biotechnology products have seen rapid growth over the past few decades and continue to dominate the global pharmaceutical market. Advances in MS instrumentation and techniques have enhanced protein characterization capabilities and supported an increased development of biopharmaceutical products.

Areas covered: This review describes recent developments in MS-based biotherapeutic analysis including sequence determination, post-translational modifications (PTMs) and higher order structure (HOS) analysis along with improvements in ionization and dissociation methods. An outlook of emerging applications of MS in the lifecycle of product development such as comparability, biosimilarity and quality control practices is also presented.

Expert commentary: MS-based methods have established their utility in the analysis of new biotechnology products and their lifecycle appropriate implementation. In the future, MS will likely continue to grow as one of the leading protein identification and characterization techniques in the biopharmaceutical industry landscape.     

29 Accelerating nucleic acid design using pre-selected sequences

Nanoscale nucleic acids could potentially be designed to be catalysts, pharmaceuticals, or probes for detecting pathogens. We hypothesize that designing nucleic acid molecules from pre-selected sequences, rather than from random sequences, would increase the speed of designing large molecules and also increase the accuracy of design. Helices should be formed in the optimal folding free energy change range, have maximal structure probability, and minimal ensemble defect. Loops should be composed of sequences with the lowest ensemble free energy change. All sequences should have low tendency to cross- and self-hybridize. These features are observed in RNA sequences with known structure.We demonstrate that preselected sequences and accelerate the design of structures that are mimics of biologically relevant structures. This is implemented as a new structure design component of RNAstructure (http://rna.urmc.rochester.edu/RNAstructure.html). This work is a collaboration with Celadon Laboratories, Inc. (http://www.celadonlabs.com/).     

Proteomic approaches for cancer epigenetics research

Introduction: Epigenetic dysregulation drives or supports numerous human cancers. The chromatin landscape in cancer cells is often marked by abnormal histone post-translational modification (PTM) patterns and by aberrant assembly and recruitment of protein complexes to specific genomic loci. Mass spectrometry-based proteomic analyses can support the discovery and characterization of both phenomena.

Areas covered: We broadly divide this literature into two parts: ‘modification-centric’ analyses that link histone PTMs to cancer biology; and ‘complex-centric’ analyses that examine protein–protein interactions that occur de novo as a result of oncogenic mutations. We also discuss proteomic studies of oncohistones. We highlight relevant examples, discuss limitations, and speculate about forthcoming innovations regarding each application.

Expert commentary: ‘Modification-centric’ analyses have been used to further understanding of cancer’s histone code and to identify associated therapeutic vulnerabilities. ‘Complex-centric’ analyses have likewise revealed insights into mechanisms of oncogenesis and suggested potential therapeutic targets, particularly in MLL-associated leukemia. Proteomic experiments have also supported some of the pioneering studies of oncohistone-mediated tumorigenesis. Additional applications of proteomics that may benefit cancer epigenetics research include middle-down and top-down histone PTM analysis, chromatin reader profiling, and genomic locus-specific protein identification. In the coming years, proteomic approaches will remain powerful ways to interrogate the biology of cancer.     

The HuGeMap Database: interconnection and visualization of human genome maps.

The HuGeMap database stores the major genetic and physical maps of the human genome. HuGeMap is accessible on the Web at http://www. infobiogen.fr/services/Hugemap and through a CORBA server. A standard genome map data format for the interconnection of genome map databases was defined in collaboration with the EBI. The HuGeMap CORBA server provides this interconnection using the interface definition language IDL. Two graphical user interfaces were developed for the visualization of the HuGeMap data: ZoomMap (http://www.infobiogen.fr/services/zomit/Zoom Map.html) for navigation by zooming and data transformation via magic lenses, and MappetShow (http://www.infobiogen.fr/services/Mappet) for visualizing and comparing maps.