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.

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).

New bioinformatics resources for metabolomics.

We recently developed two databases and a laboratory information system as resources for the metabolomics community. These tools are freely available and are intended to ease data analysis in both MS and NMR based metabolomics studies. The first database is a metabolomics extension to the BioMagResBank (BMRB, http://www.

BioMagResBank.

The BioMagResBank (BMRB: www.bmrb.wisc.

Stable isotope assisted assignment of elemental compositions for metabolomics.

Assignment of individual compound identities within mixtures of thousands of metabolites in biological extracts is a major challenge for metabolomic technology. Mass spectrometry offers high sensitivity over a large dynamic range of abundances and molecular weights but is limited in its capacity to discriminate isobaric compounds. In this article, we have extended earlier studies using isotopic labeling for elemental composition elucidation (Rodgers, R.