PRotein Ontology (PRO) Release 55.0 (15-Feb-2018)

There are 215130 PRO terms in the Protein Ontology.
   81 terms are in the 'external' category.
   158 terms are in the 'organism-seqgroup' category.
   417 terms are in the 'family' category.
  23537 terms are in the 'gene' category.
  8328 terms are in the 'sequence' category.
  5073 terms are in the 'modification' category.
   211 terms are in the 'complex' category.
   143 terms are in the 'organism-family' category.
  98062 terms are in the 'organism-gene' category.
  69978 terms are in the 'organism-sequence' category.
  6573 terms are in the 'organism-modification' category.
   389 terms are in the 'organism-complex' category.
   47 terms are in the 'union' category.
2527 terms have some kind of annotation, codifying the information from 1691 papers.
  4446 connections to GO (1724 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) A 'property_value' line has been added to the OBO format files to indicate the license information.

_Forthcoming changes_

1) We will phase out ftp as default method for downloads, switching instead to http. Downloads that use PURLs (such as http://purl.obolibrary.org/obo/pr.owl, which is the preferred method) will not be affected, as the target file and method will update automatically.