Propeptide

This subsection of the ‘Sequence annotation (Features)’ section describes a propeptide, which is a part of a protein that is cleaved during maturation or activation. Once cleaved, a propeptide generally has no independent biological function.

Examples: P29958, P21588

This subsection is only present when the existence of the propeptide has been demonstrated experimentally in the protein concerned or in a closely related homolog.
Example: Q8WXQ8

We do not annotate the 2 to 4 basic amino acid residues regions produced by basic-specific proconvertase cleavage as a ‘Propeptide’, since these short oligopeptides are degraded and are generally not considered as bona fide propeptides.
Example: P19802 ; Related keyword: Cleavage on pair of basic residues