We have inferred structural, evolutionary, and functional characteristics of LOC56985, a hypothetical protein coded by the gene C17orf48, using bioinformatic analysis. Sequence analysis identified LOC56985 as a metallophosphoesterase with high similarity orthologs present in vertebrates and plants. The protein's structure is a 4-layer sandwich fold and contains the calcineurin-like phosphoesterase domain (PF00149). Structural studies, utilising the x-ray structure of an ortholog from zebra fish, indicates that LOC56985 is most likely a purple acid phosphatase (PAP). Sequence searches do not support the structural similarities as a BLASTp search showed no PAPs with high e-values. A multiple sequence alignment and subsequent phylogenetic tree show that vertical gene transmission is the major form of evolution of LOC56985. There is some unpublished experimental data that shows that the rat ortholog is an Mn2+ dependant ADP-ribose/ CDP-alcohol pyrophosphatase (ADPRibase-Mn), an intracellular regulator of ion channel activity. On current evidence, LOC56985 can be described as a PAP-like metallo-dependant phosphatase (PMDP).