This family of proteins found in operons encoding phosphonate C-P lyase systems as is observed in E. coli and is a member of the metallo-beta-lactamase superfamily (pfam00753). As defined by this model, all instances of this protein are associated with the C-P lyase, but not all genomes containing the C-P lyase system contain phnP.
Jiyao W et al.(2023). "The conserved domain database in 2023.",