ACPYPE - AnteChamber PYthon Parser interfacE.

RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are.BACKGROUND: ACPYPE (or AnteChamber PYthon Parser interfacE) is a wrapper script around the ANTECHAMBER software that simplifies the generation of small molecule topologies and parameters for a variety of molecular dynamics programmes like GROMACS, CHARMM and CNS. It is written in the Python programming language and was developed as a tool for interfacing with other Python based applications such as the CCPN software suite (for NMR data analysis) and ARIA (for structure calculations from NMR data). ACPYPE is open source code, under GNU GPL v3, and is available as a stand-alone application at http://www.ccpn.ac.uk/acpype and as a web portal application at http://webapps.ccpn.ac.uk/acpype. FINDINGS: We verified the topologies generated by ACPYPE in three ways: by comparing with default AMBER topologies for standard amino acids; by generating and verifying topologies for a large set of ligands from the PDB; and by recalculating the structures for 5 protein-ligand complexes from the PDB. CONCLUSIONS: ACPYPE is a tool that simplifies the automatic generation of topology and parameters in different formats for different molecular mechanics programmes, including calculation of partial charges, while being object oriented for integration with other applications

Documenting marine species traits in the World Register of Marine Species (WoRMS): current status, future plans and encountered challenges

The importance of describing species patterns and the underlying processes explaining these patterns is essential to assess the status and future evolution of marine ecosystems. This requires biological information on functional and structural species traits such as feeding ecology, body size, reproduction, life history, etc.To accommodate this need, the World Register of Marine Species (WoRMS) (WoRMS Editorial Board 2017) is expanding its content with trait information (Costello et al. 2015), subdivided into 3 main categories: (1) taxonomy related traits, e.g. paraphyletic groups, (2) biological and ecological traits-specific characteristics of a taxon, e.g. body size or feeding type and (3) human defined traits, e.g. the legal protection status of species, whether a species is introduced, harmful, or used as an ecological indicator.Initially, priority was given to the inclusion of traits that could be applied to the majority of marine taxa and where the information was easily available. The main driver for this approach was that the inclusion of these traits should result in new research, which in turn would drive improvements in the quality and quantity of trait information. Pilot projects were carried out for different species groups, allowing a thorough documentation of a selection of traits. In parallel, a standard vocabulary was put together (http://www.marinespecies.org/traits/wiki/), based on already existing resources to cover all marine life. All documented traits needed to be compliant with this vocabulary, in order to make the data as widely useable as possible, across groups. Defining a trait across all marine life is not trivial, as scientists can use terms in a different way between groups. This stresses the importance for users to realize these differences in terminology, before they analyse a trait across all taxa.Some traits were thought to be quite straightforward to document, although practice proved otherwise. Such a trait is body size, where the aim was to document the numerical value of the ‘maximum body size in length’. In reality, a lot of variation is possible (e.g. for fish: fork length versus standard length) and maximum size is not always considered relevant from an ecological point of view. On the other hand, documenting numerical body size for each marine species is quite time consuming. Therefore, a complementary size trait will be documented, indicating whether taxa are considered as micro, meio, macro or mega.Whereas the initial approach was to complete the register for each tackled trait relevant for all marine species, we now complement this by (1) documenting several traits within a specific group, regardless whether this trait is also present in other taxon groups, and (2) documenting one specific trait, covering a variety – but not all – taxonomic groups, e.g. the composition of the skeleton for calcareous animals.Where possible, we aim to document a trait on a higher taxonomic level to allow the work to progress more rapidly. As the database allows top-down inheritance of traits, exceptions can easily be documented. In addition, collaborations are sought with already running initiatives such as Encyclopedia of Life.Very soon, all the documented traits will be searchable through the Marine Species Traits Portal. The human-defined traits are already accessible through the EMODnet Biology Portal (http://www.emodnet-biology.eu/toolbox), in combination with distribution information from the European Ocean Biogeographic Information System (EurOBIS; www.eurobis.org; Vandepitte et al. 2011; Vandepitte et al. 2015) and taxonomy from WoRMS (www.marinespecies.org). Through the LifeWatch Taxonomic Backbone (LW-TaxBB) (http://www.lifewatch.be/data-services/), services are offered to access these traits, combined with data and information from other resources such as WoRMS and (Eur)OBIS.We would like to acknowledge the EMODnet Biology and the LifeWatch project, in which the Flanders Marine Institute (VLIZ) – host institute of WoRMS – is responsible for the development of the LW-TaxBB. Both projects provide funding for the documentation of trait data and development of services allowing researchers to easily access the available data, in combination with data from other sources

Structure calculation, refinement and validation using CcpNmr Analysis

CcpNmr Analysis provides a streamlined pipeline for both NMR chemical shift assignment and structure determination of biological macromolecules. In addition, it encompasses tools to analyse the many additional experiments that make NMR such a pivotal technique for research into complex biological questions. This report describes how CcpNmr Analysis can seamlessly link together all of the tasks in the NMR structure-determination process. It details each of the stages from generating NMR restraints [distance, dihedral,hydrogen bonds and residual dipolar couplings (RDCs)],exporting these to and subsequently re-importing them from structure-calculation software (such as the programs CYANA or ARIA) and analysing and validating the results obtained from the structure calculation to, ultimately, the streamlined deposition of the completed assignments and the refined ensemble of structures into the PDBe repository. Until recently, such solution-structure determination by NMR has been quite a laborious task, requiring multiple stages and programs. However, with the new enhancements to CcpNmr Analysis described here, this process is now much more intuitive and efficient and less error-prone

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

E-MSD: improving data deposition and structure quality

The Macromolecular Structure Database (MSD) () [H. Boutselakis, D. Dimitropoulos, J. Fillon, A. Golovin, K. Henrick, A. Hussain, J. Ionides, M. John, P. A. Keller, E. Krissinel et al. (2003) E-MSD: the European Bioinformatics Institute Macromolecular Structure Database. Nucleic Acids Res., 31, 458–462.] group is one of the three partners in the worldwide Protein DataBank (wwPDB), the consortium entrusted with the collation, maintenance and distribution of the global repository of macromolecular structure data [H. Berman, K. Henrick and H. Nakamura (2003) Announcing the worldwide Protein Data Bank. Nature Struct. Biol., 10, 980.]. Since its inception, the MSD group has worked with partners around the world to improve the quality of PDB data, through a clean up programme that addresses inconsistencies and inaccuracies in the legacy archive. The improvements in data quality in the legacy archive have been achieved largely through the creation of a unified data archive, in the form of a relational database that stores all of the data in the wwPDB. The three partners are working towards improving the tools and methods for the deposition of new data by the community at large. The implementation of the MSD database, together with the parallel development of improved tools and methodologies for data harvesting, validation and archival, has lead to significant improvements in the quality of data that enters the archive. Through this and related projects in the NMR and EM realms the MSD continues to improve the quality of publicly available structural data

FAD binding, cobinamide binding and active site communication in the corrin reductase (CobR)

Adenosylcobalamin, the coenzyme form of vitamin B12, is one Nature's most complex coenzyme whose de novo biogenesis proceeds along either an anaerobic or aerobic metabolic pathway. The aerobic synthesis involves reduction of the centrally chelated cobalt metal ion of the corrin ring from Co(II) to Co(I) before adenosylation can take place. A corrin reductase (CobR) enzyme has been identified as the likely agent to catalyse this reduction of the metal ion. Herein, we reveal how Brucella melitensis CobR binds its coenzyme FAD (flavin dinucleotide) and we also show that the enzyme can bind a corrin substrate consistent with its role in reduction of the cobalt of the corrin ring. Stopped-flow kinetics and EPR reveal a mechanistic asymmetry in CobR dimer that provides a potential link between the two electron reduction by NADH to the single electron reduction of Co(II) to Co(I)

Sediment structure and physicochemical changes following tidal inundation at a large open coast managed realignment site

Managed realignment (MR) schemes are being implemented to compensate for the loss of intertidal saltmarsh habitats by breaching flood defences and inundating the formerly defended coastal hinterland. However, studies have shown that MR sites have lower biodiversity than anticipated, which has been linked with anoxia and poor drainage resulting from compaction and the collapse of sediment pore space caused by the site's former terrestrial land use. Despite this proposed link between biodiversity and soil structure, the evolution of the sediment sub-surface following site inundation has rarely been examined, particularly over the early stages of the terrestrial to marine or estuarine transition. This paper presents a novel combination of broad- and intensive-scale analysis of the sub-surface evolution of the Medmerry Managed Realignment Site (West Sussex, UK) in the three years following site inundation. Repeated broad-scale sediment physiochemical datasets are analysed to assess the early changes in the sediment subsurface and the preservation of the former terrestrial surface, comparing four locations of different former land uses. Additionally, for two of these locations, high-intensity 3D-computed X-ray microtomography and Itrax micro-X-ray fluorescence spectrometry analyses are presented. Results provide new data on differences in sediment properties and structure related to the former land use, indicating that increased agricultural activity leads to increased compaction and reduced porosity. The presence of anoxic conditions, indicative of poor hydrological connectivity between the terrestrial and post-inundation intertidal sediment facies, was only detected at one site. This site has experienced the highest rate of accretion over the terrestrial surface (ca. 7 cm over 36 months), suggesting that poor drainage is caused by the interaction (or lack of) between sediment facies rather than the former land use. This has significant implications for the design of future MR sites in terms of preparing sites, their anticipated evolution, and the delivery of ecosystem services