Acid phosphatase, plant (IPR010028)

Short name: Acid_phosphatase_pln

Overlapping homologous superfamilies

Family relationships


This entry represents a family of acid phosphatase [PMID: 9758760, PMID: 9193092] from plants which are closely related to the class B non-specific acid phosphatase OlpA (IPR006423, which is believed to be a 5'-nucleotide phosphatase) and somewhat more distantly to another class B phosphatase, AphA (IPR010025). Together these three clades define a subfamily of Acid phosphatase (Class B), which corresponds to the IIIB subfamily of the haloacid dehalogenase (HAD) superfamily of aspartate nucleophile hydrolases. It has been reported that the best substrates were purine 5'-nucleoside phosphates [PMID: 9758760]. This is in concordance with the assignment of the Haemophilus influenzae hel protein (from IPR006423) as a 5'-nucleotidase, however there is presently no other evidence to support this specific function for this family of plant phosphatases. Many genes from this family have been annotated as vegetative storage proteins (VSPs) due to their close homology with these earlier-characterised gene products which are highly expressed in leaves. There are significant differences however, including expression levels and distribution [PMID: 9747802]. The most important difference is the lack in authentic VSPs of the nucleophilic aspartate residue, which is instead replaced by serine, glycine or asparagine. Thus these proteins can not be expected to be active phosphatases. This issue was confused by the publication in 1992 of an article claiming activity for the Glycine max (Soybean) VSP [PMID: 1639823]. In 1994 this assertion was refuted by the separation of the activity from the VSP. This entry explicitly excludes the VSPs which lack the nucleophilic aspartate. The possibility exists, however, that some members of this family may, while containing all of the conserved HAD-superfamily catalytic residues, lack activity and have a function related to the function of the VSPs rather than the acid phosphatases.

GO terms

Biological Process

No terms assigned in this category.

Molecular Function

GO:0003993 acid phosphatase activity

Cellular Component

No terms assigned in this category.

Contributing signatures

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