The proteins represented by this model are close relatives of the plant acid phosphatases (TIGR01675), are limited to members of the Phaseoleae including Glycine max (soybean) and Phaseolus vulgaris (kidney bean). These proteins are highly expressed in the leaves of repeatedly depodded plants. VSP differs most strinkingly from the acid phosphatases in the lack of the conserved nucleophilic aspartate residue in the N-terminus, thus, they should be inactive as phosphatases. This issue was confused by the publication in 1992 of an article claiming activity for the Glycine max VSP. In 1994 this assertion was refuted by the separation of the activity from the VSP.