An allele of the Prot locus in maize is a variant for the site of protein processing

An allele of the Prot locus, which encodes a major globulin of the maize scutellum, is a variant for a site of protein processing. Segregation analysis and recombination mapping indicate that the variant is an allele of the Prot locus. Designated Prot-V, this allele specifies three polypeptides, V1, V2, and V3. The V1 polypeptide is incompletely processed during the proteolytic processing step catalyzed by the product of the Mep locus. Cyanogen bromide cleavage studies support the precursor-product relationship between V1 and V2. The V1 product is shortened with respect to other PROT′ proteins and it is postulated that the normal site of MEP processing has been removed by this foreshortening.