DisProt 7.0: a major update of the database of disordered proteins

Abstract

The Database of Protein Disorder (DisProt, URL: www.disprot.org) has been significantly updated and upgraded since its last major renewal in 2007. The current release holds information on more than 800 entries of IDPs/IDRs, i.e. intrinsically disordered proteins or regions that exist and function without a well-defined three-dimensional structure. We have re-curated previous entries to purge DisProt from conflicting cases, and also upgraded the functional classification scheme to reflect continuous advance in the field in the past 10 years or so. We define IDPs as proteins that are disordered along their entire sequence, i.e. entirely lack structural elements, and IDRs as regions that are at least five consecutive residues without well-defined structure. We base our assessment of disorder strictly on experimental evidence, such as X-ray crystallography and nuclear magnetic resonance (primary techniques) and a broad range of other experimental approaches (secondary techniques). Confident and ambiguous annotations are highlighted separately. DisProt 7.0 presents classified knowledge regarding the experimental characterization and functional annotations of IDPs/IDRs, and is intended to provide an invaluable resource for the research community for a better understanding structural disorder and for developing better computational tools for studying disordered proteins.

Figure 1.

DisProt sample entry, human p53 protein (DP00086). Several experiments have been carried out to characterize the human p53 protein. DisProt reports literature evidence for IDRs. In particular, 11 different IDR evidences (Region Evidences) have been collected from nine different papers by two different curators. Most of these are related to the N-terminus and come from different types of experiments (Disorder Region Details). Disorder regions and the number of DisProt evidences, separated into confident and ambiguous annotations, can be compared with structural information from the Pfam and MobiDB databases in the Disorder Overview. DisProt also provides function annotation of IDRs by reporting molecular function, transition and partner terms (Functional Annotation). A literature reference is provided for each annotated IDR, linked to the relevant PubMed entry.

Figure 2.

Distribution of disorder segment lengths. Segment lengths are binned in groups of 10 residues, e.g. the column 10 showing lengths between 10 and 19 residues. The current DisProt release is distinguished by experimental technique (X-ray in green, NMR in blue and other methods in red). The previous DisProt release is shown in a single gray bar as it did not have the experimental technique in a machine-readable format.