<p>In a number of species, including <taxon tax_id="562">Escherichia coli</taxon>, the histidine biosynthetic enzymes imidazole glycerol phosphate dehydratase and histidinol phosphatase are found together in the bifunctional protein HisB. This family represents a protein closely related to the histidinol phosphatase domain of HisB. The protein is found both in <taxon tax_id="210">Helicobacter pylori</taxon>, for which the histidine biosynthetic pathway appears to be absent, and in species that also have a bifunctional HisB protein.</p><p>Members of this family have been characterised as D,D-heptose 1,7-bisphosphate phosphatase, which converts the D-glycero-beta-D-manno-heptose 1,7-bisphosphate intermediate into D-glycero-beta-D-manno-heptose 1-phosphate by removing the phosphate group at the C-7 position. </p>