49 research outputs found
Sox genes in the coral Acropora millepora: divergent expression patterns reflect differences in developmental mechanisms within the Anthozoa
Background: Sox genes encode transcription factors that function in a wide range of developmental processes across the animal kingdom. To better understand both the evolution of the Sox family and the roles of these genes in cnidarians, we are studying the Sox gene complement of the coral, Acropora millepora (Class Anthozoa).\ud
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Results: Based on overall domain structures and HMG box sequences, the Acropora Sox genes considered here clearly fall into four of the five major Sox classes. AmSoxC is expressed in the ectoderm during development, in cells whose morphology is consistent with their assignment as sensory neurons. The expression pattern of the Nematostella ortholog of this gene is broadly similar to that of AmSoxC, but there are subtle differences – for example, expression begins significantly earlier in Acropora than in Nematostella. During gastrulation, AmSoxBb and AmSoxB1 transcripts are detected only in the presumptive ectoderm while AmSoxE1 transcription is restricted to the presumptive endoderm, suggesting that these Sox genes might play roles in germ layer specification. A third type B Sox gene, AmSoxBa, and a Sox F gene AmSoxF also have complex and specific expression patterns during early development. Each of these genes has a clear Nematostella ortholog, but in several cases the expression pattern observed in Acropora differs significantly from that reported in Nematostella.\ud
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Conclusion: These differences in expression patterns between Acropora and Nematostella largely reflect fundamental differences in developmental processes, underscoring the diversity of mechanisms within the anthozoan Sub-Class Hexacorallia (Zoantharia)
NRG-CING: integrated validation reports of remediated experimental biomolecular NMR data and coordinates in wwPDB
For many macromolecular NMR ensembles from the Protein Data Bank (PDB) the experiment-based restraint lists are available, while other experimental data, mainly chemical shift values, are often available from the BioMagResBank. The accuracy and precision of the coordinates in these macromolecular NMR ensembles can be improved by recalculation using the available experimental data and present-day software. Such efforts, however, generally fail on half of all NMR ensembles due to the syntactic and semantic heterogeneity of the underlying data and the wide variety of formats used for their deposition. We have combined the remediated restraint information from our NMR Restraints Grid (NRG) database with available chemical shifts from the BioMagResBank and the Common Interface for NMR structure Generation (CING) structure validation reports into the weekly updated NRG-CING database (http://nmr.cmbi.ru.nl/NRG-CING). Eleven programs have been included in the NRG-CING production pipeline to arrive at validation reports that list for each entry the potential inconsistencies between the coordinates and the available experimental NMR data. The longitudinal validation of these data in a publicly available relational database yields a set of indicators that can be used to judge the quality of every macromolecular structure solved with NMR. The remediated NMR experimental data sets and validation reports are freely available online
BioMagResBank (BMRB) as a partner in the Worldwide Protein Data Bank (wwPDB): new policies affecting biomolecular NMR depositions
We describe the role of the BioMagResBank (BMRB) within the Worldwide Protein Data Bank (wwPDB) and recent policies affecting the deposition of biomolecular NMR data. All PDB depositions of structures based on NMR data must now be accompanied by experimental restraints. A scheme has been devised that allows depositors to specify a representative structure and to define residues within that structure found experimentally to be largely unstructured. The BMRB now accepts coordinate sets representing three-dimensional structural models based on experimental NMR data of molecules of biological interest that fall outside the guidelines of the Protein Data Bank (i.e., the molecule is a peptide with 23 or fewer residues, a polynucleotide with 3 or fewer residues, a polysaccharide with 3 or fewer sugar residues, or a natural product), provided that the coordinates are accompanied by representation of the covalent structure of the molecule (atom connectivity), assigned NMR chemical shifts, and the structural restraints used in generating model. The BMRB now contains an archive of NMR data for metabolites and other small molecules found in biological systems
The NMR restraints grid at BMRB for 5,266 protein and nucleic acid PDB entries
Several pilot experiments have indicated that improvements in older NMR structures can be expected by applying modern software and new protocols (Nabuurs et al. in Proteins 55:483–186, 2004; Nederveen et al. in Proteins 59:662–672, 2005; Saccenti and Rosato in J Biomol NMR 40:251–261, 2008). A recent large scale X-ray study also has shown that modern software can significantly improve the quality of X-ray structures that were deposited more than a few years ago (Joosten et al. in J. Appl Crystallogr 42:376–384, 2009; Sanderson in Nature 459:1038–1039, 2009). Recalculation of three-dimensional coordinates requires that the original experimental data are available and complete, and are semantically and syntactically correct, or are at least correct enough to be reconstructed. For multiple reasons, including a lack of standards, the heterogeneity of the experimental data and the many NMR experiment types, it has not been practical to parse a large proportion of the originally deposited NMR experimental data files related to protein NMR structures. This has made impractical the automatic recalculation, and thus improvement, of the three dimensional coordinates of these structures. We here describe a large-scale international collaborative effort to make all deposited experimental NMR data semantically and syntactically homogeneous, and thus useful for further research. A total of 4,014 out of 5,266 entries were ‘cleaned’ in this process. For 1,387 entries, human intervention was needed. Continuous efforts in automating the parsing of both old, and newly deposited files is steadily decreasing this fraction. The cleaned data files are available from the NMR restraints grid at http://restraintsgrid.bmrb.wisc.edu
Outcome of the First wwPDB Hybrid / Integrative Methods Task Force Workshop
Structures of biomolecular systems are increasingly computed by integrative modeling that relies on varied types of experimental data and theoretical information. We describe here the proceedings and conclusions from the first wwPDB Hybrid/Integrative Methods Task Force Workshop held at the European Bioinformatics Institute in Hinxton, UK, on October 6 and 7, 2014. At the workshop, experts in various experimental fields of structural biology, experts in integrative modeling and visualization, and experts in data archiving addressed a series of questions central to the future of structural biology. How should integrative models be represented? How should the data and integrative models be validated? What data should be archived? How should the data and models be archived? What information should accompany the publication of integrative models
Cnidarians and ancestral genetic complexity in the animal kingdom
Eleven of the twelve recognized wingless (Wnt) subfamilies are represented in the sea anemone Nematostella vectensis, indicating that this developmentally important gene family was already fully diversified in the common ancestor of 'higher' animals. In deuterostomes, although duplications have occurred, no novel subfamilies of Wnts have evolved. By contrast, the protostomes Drosophila and Caenorhabditis have lost half of the ancestral Wnts. This pattern - loss of genes from an ancestrally complex state - might be more important in animal evolution than previously recognized
Cnidarians and ancestral genetic complexity in the animal kingdom
Eleven of the twelve recognized wingless (Wnt) subfamilies are represented in the sea anemone Nematostella vectensis, indicating that this developmentally important gene family was already fully diversified in the common ancestor of ‘higher’ animals. In deuterostomes, although duplications have occurred, no novel subfamilies of Wnts have evolved. By contrast, the protostomes Drosophila and Caenorhabditis have lost half of the ancestral Wnts. This pattern – loss of genes from an ancestrally complex state – might be more important in animal evolution than previously recognized.http://www.sciencedirect.com/science/journal/0168952