Nucellin (IPR033823)

Short name: Nucellin

Overlapping homologous superfamilies

Domain relationships


Nucellin (MEROPS identifier A01.073) is an important regulator of a nucellar cell's progressive degradation after ovule fertilization. This degradation is a characteristic of programmed cell death. Nucellin is a plant aspartic endopeptidase specifically expressed in nucellar cells during degradation [PMID: 9426602, PMID: 15659452]. The enzyme is characterized by having two aspartic endopeptidase catalytic site motifs, Asp-Thr-Gly-Ser in the N-terminal and Asp-Ser-Gly-Ser in the C-terminal region, and two other regions nearly identical to two regions of plant aspartic proteases. An aspartic endopeptidase is a bilobal enzyme, with each lobe contributing a catalytic Asp residue, with an extended active site cleft localized between the two lobes of the molecule. One lobe may be evolved from the other through ancient gene-duplication event. Although the three-dimensional structures of the two lobes are very similar, the amino acid sequences are more divergent, except for the conserved catalytic site motif [PMID: 9426602].

This entry represents the peptidase domain of nucellin.

GO terms

Biological Process

No terms assigned in this category.

Molecular Function

GO:0004190 aspartic-type endopeptidase activity

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.