PRotein Ontology (PRO) Release 50.0 (22-Sep-2016) There are 208290 PRO terms in the Protein Ontology. 57 terms are in the 'external' category. 403 terms are in the 'family' category. 23560 terms are in the 'gene' category. 8323 terms are in the 'sequence' category. 6677 terms are in the 'modification' category. 212 terms are in the 'complex' category. 34 terms are in the 'organism-family' category. 93389 terms are in the 'organism-gene' category. 68413 terms are in the 'organism-sequence' category. 6420 terms are in the 'organism-modification' category. 384 terms are in the 'organism-complex' category. 117 terms are in the 'union' category. 2513 terms have some kind of annotation, codifying the information from 1673 papers. 4416 connections to GO (1710 PRO terms). 292 connections to MOD (255 PRO terms). 616 connections to Pfam (369 PRO terms). 338 connections to SO (317 PRO terms). 349 annotations of a phenotype (342 PRO terms). The ontology includes a subset of terms from other ontologies and resources that are used for logical definitions. _Current changes_ 1) From this release on the default download of PRO (http://purl.obolibrary.org/obo/pr.obo) will point to the reasoned version (called pro_reasoned.obo). The previous default was pro_nonreasoned.obo. 2) A new relation has been added "non-covalently_bound_to". Example: PR:000037031 represents the class of GTP-binding protein rho3 in its GTP-bound form [Typedef] id: non-covalently_bound_to name: non-covalently_bound_to def: "A relation that holds between two distinct chemical entities that are held in close proximity to each other specifically via the force of non-covalent interactions. Such entities will, at all times of the interaction, colocalize with each other." [PRO:DAN] domain: CHEBI:24431 ! chemical entity range: CHEBI:24431 ! chemical entity is_symmetric: true 3) We introduced a new standard comment, "Status=unreviewed.", to indicate proteoforms that have been automatically generated based on data integrated from external resources but have not yet been reviewed by a curator. Example:PR:000046210 [Term] id: PR:000046210 name: heterogeneous nuclear ribonucleoprotein A0 phosphorylated 1 (mouse) def: "A heterogeneous nuclear ribonucleoprotein A0 (mouse) that has been post-translationally modified to include phosphorylation at a position equivalent to Ser-84 of the amino acid sequence represented by UniProtKB:Q9CX86. UniProtKB:Q9CX86, Ser-84, MOD:00046." [PMID:12456657, iPTMnet:Q9CX86] comment: Category=organism-modification. Evidence=(ECO:0000006, based on PMID:12456657). Status=unreviewed. synonym: "mHNRNPA0/Phos:1" EXACT PRO-short-label [PRO:DNx] is_a: PR:Q9CX86 ! heterogeneous nuclear ribonucleoprotein A0 (mouse) relationship: has_part MOD:00046 ! O-phospho-L-serine relationship: only_in_taxon NCBITaxon:10090 ! Mus musculus