<p>This protein family has a phylogenetic distribution very similar to that of coenzyme pyrroloquinoline quinone (PQQ) biosynthesis enzymes, as shown by partial phylogenetic profiling. These proteins use PPQ as a cofactor. Members of this family have several predicted transmembrane helices in the N-terminal region, and includes:</p><p> <ul> <li>Quinoprotein glucose dehydrogenase (<db_xref db="EC" dbkey="1.1.5.2"/>) of <taxon tax_id="562">Escherichia coli</taxon>, which is probably involved in energy conservation rather than in sugar metabolism [<cite idref="PUB00044661"/>].</li> </ul> </p><p> <ul> <li>Quinate/shikimate dehydrogenase of <taxon tax_id="62977">Acinetobacter sp.</taxon> (strain ADP1) (<db_xref db="EC" dbkey="1.1.99.25"/>), which can act either on quinate or on shikimate, and is involved in the metabolism of aromatic compounds.</li> </ul> </p> <p>Sequences closely related, except for the absence of the N-terminal hydrophobic region, and not included in this entry include pyrroloquinoline quinone (PQQ)-dependent glycerol (<db_xref db="EC" dbkey="1.1.99.22"/>) and other polyol (sugar alcohol) dehydrogenases.</p> PQQ-dependent membrane bound dehydrogenase, glucose/quinate/shikimate-related