<p>This subfamily falls within the Haloacid Dehalogenase (HAD) superfamily of aspartate-nucleophile hydrolases. The Class II subfamilies are characterised by a domain that is located between the second and third conserved catalytic motifs of the superfamily domain. The IIB subfamily is distinguished from the IIA subfamily (<db_xref db="INTERPRO" dbkey="IPR006357"/>) by homology and the predicted secondary structure of this domain by PSI-PRED. The IIB subfamilys Class II domain has the following predicted structure: Helix-Sheet-Sheet-(Helix or Sheet)-Helix-Sheet-(variable)-Helix-Sheet-Sheet. The IIB subfamily consists of trehalose-6-phosphatase, plant and cyanobacterial sucrose-phosphatase and a closely related group of bacterial and archaeal sequences, eukaryotic phosphomannomutase, a large subfamily of Cof-like hydrolases, containing many closely related bacterial sequences, a hypothetical equivalog containing the <taxon tax_id="562">Escherichia coli</taxon> YedP protein, as well as two other small clusters whose relationship to the other groups is unclear.</p>